Readers questions

Write hear Your questions, pls. – Ide írjatok kérdéseket
In short form, and in the first line the body or the lens name.
Röviden, és az első sorban a váz vagy az optika névét feltüntetve.

672 Responses to Readers questions

  1. Gonzalo says:

    Just got a Canon 70-200 F/4 IS USM (version 1) and noticed that the stabilizer works but it often makes a clicking noise and then it disengages.
    I’ve seen that you have a hungarian pdf describing something similar, right? and it ended up being a cracked plastic ring/gear. Did that lens have a similar issue?
    I saw that I can buy the replacement ring in aliexpress and change it, but my question is, does the lens need optical realignment after disassemblying everything required to change that part?
    Many thanks!

  2. Dave says:

    Greetings I am currently working on a Canon 5D Mark 4. With a error 20 issue. I believe it is the shutter assembly due to the end user saying it was dropped. I have been reading more and more into the repair. And it appears that the sensor might need to be adjusted after it is pulled off.
    Is this the correct procedure for this camera body?

    Thank you !

    • canonrepair says:

      This is a general method, should work on any body.
      I will try not to forget to make the calculation excel available

      • Dave says:

        Thank you , according to a tech I spoke with online , they said that this was impossible to do at home, and required a expensive canon FB tool. Many times the shutter replacement guides do not add in the needed recalibration.
        Copied below are his comments , thank you again for the speedy response!

      • canonrepair says:

        I dont know how this links work – could you better send to my email normal pictures: janos at camerarepair dot hu

        Yes, an OFFICIAL canon adjustment needs a special equipment, and you can do it in one step.
        My method needs more steps – but is incomparable cheaper.

    • Filip says:

      Before replacing shutter, check the mirror motor. Almost all of the 5D mk IV cameras that I worked on with error 20 had bad mirror motor.
      Bad motor will be shorted. You can check the motor by removing the front camera housing and applying 4-5V to the motor terminals, red wire is positive. Limit the current to 0.5A, otherwise if motor is shorted magic smoke will escape…
      If motor is bad there is no way to replace it without complete dissasembly of the camera. That means you need to measure exact position of the sensor plate relative to the mount, before you take things apart. On this model there are three small polished “pins” next to the adjusting screws that are used for reference measurement.
      Sensor screws are Torx 6.


  3. KK says:

    Hi there, what is the small cable on the inside on the Canon 7D called -the one with the yellow connector – connecting at the bottom of the camera?

  4. Erwin says:

    7D, dark images

    Hi János,
    I have a 7D, which makes very (by about 4 stops too) dark images in all automatic modes by choosing (and displaying) the exposure time too short.
    Images are ok, when shot in LiveView: exposure times are much longer then.
    Images are also ok in manual mode (with exposure times selected comparable to others cameras).
    So I’m quite sure that exposure metering must be the reason. But changing the complete viewfinder unit against a new one didn’t change anything.
    Also, changing the main did not help.

    Any idea what could be wrong?

    • canonrepair says:

      Cable from exposure meter (which is in the top of the viewfinder, or mainboard.
      In general case could be the exposure meter chip too.
      What about the screen matte? Is the original?

      • Erwin says:

        The viewfinder replacement included the metering chip and cable and also the screen matte.

        @bigdave12345: Yes, I cleared all settings including the individual functions.

      • canonrepair says:

        in that case, I am afraid: motherboard.

      • Erwin says:

        This was my next thought, too. But after replacing the main board, the issue still was alive.
        I also replaced the socket board without any effect.

      • canonrepair says:

        But did you programmed the board for the new exposure value? It is strange to have SUCH A BIG difference – but motherboards HAVE TO be adjusted via service software.

      • Erwin says:

        I’m aware of the need to adopt a motherboard after changing, however, I can’t do it myself.
        But the replacement board was adjusted for the replacement viewfinder.
        And the sensor works fine. Really strange.

    • bigdave12345 says:



      Have you tried resetting the camera to default settings?


      Sent: Thursday, December 01, 2022 at 6:07 PM

  5. Jiří Dejmek says:

    Hello János,
    Would you be interested in blog article written by somebody else than you? I am huge fan of your work and I´d like to give back some of knoweledge I got from your articles 🙂
    Ive come across dirt cheap beater of 35-350 “L” push-pull zoom lens from 1996.
    It had been hunting AF, inner barrel was covered by some awfull grey paintjob and it had non functioning pull zoom friction clutch.
    As for now, lens is mechanically completely sorted and working after just one evening of tinkering and practically for free. With some critical findings about inner works of this lens.
    I absolutely love this beast and would love to write an article about its rehab.

  6. Tamron 17-50 for Canon,

    First of all, thanks for the incredible knowledge that you have in your blog. Keep on it!
    I have a Tamron 17-50 that have some “fractal” patterns on the front element. I treated it as fungus, and as it didn’t dissapear, so I guess it is a cement issue. I bought another 17-50 with broken electronics as donor, and I plan to change the front element, as it is much easier than reparing the electronics (probably a broken flex circuit). Do you know if I need to do any adjustment to the front element after replacing it?



    • canonrepair says:

      Hi Eduardo,
      I don’t know, how exactly the Tamron 17-50 is, but You can find out quickly: if there will be a possibility of turning the front lens after loosening of the 3 screws , then has an axial adjustment, which normally adjusts the focus on infinity to be on the same position for 17mm and 50 mm. If not, another methd for Tamron is to use some washers under the 3 scruws, which go in from the outside. BE CAREFUL BY LOOSENING, as they are NOT ALWAYS of the same size – they adjust by some Tamrons (150-600 for ex) the tilt of the front lens – so the right-left and up-down side focus.

  7. Canon EF 500mm f/4L IS USM

    Hello, I have been reading some from your blog and I would like to say thank you for such a great resource. Sadly, there is few out there. I, myself have been tinkering with my lens and tried to restore the ultrasonic motor that was working poorly. While cleaning it, I accidentally broke this plastic/acrylic half moon ring that is moving in a circular motion and being read with some sort of sensor with a small plastic piece on it as well. I believe you call it “optical encoder ring(I might be wrong here?). It tried to put it back together with glue and polish it but that made the “encoding (?”) disappear. What would be your best suggestion on how to move forward now? It would be really sad if I had to throw away the whole lens because this little plastic thing is broken and there is no spare parts 😦

    Thank you for your time and understanding.
    Best regards,
    Ted Lindström

    • canonrepair says:

      Hi Ted,
      I think, that Canon makes only a few sizes of the USM motors, and the optical encoders (incremental encoders) have probably the same pitch. You should try to get an another one from any other lens, but with the same USM size. Case You have both encoder half-rings in hand, you can probably measure them with a microscope – or just build in, an check.
      (If the pitch is different, it will make a faulty travel to focus. )

  8. Alexander says:

    Hi János,

    EF 24-105L, mk1, AF doesnt work anymore. With other main PCB – ok.
    Can you point me at stepper driver IC? I want to order and replace it separately, as I did before for another lens in same case.
    Or its only way to change whole PCB? Maybe, you also have service manual and theres any electrical diagrams or ICs specs?

    Thank you for all you doing.

  9. agittins says:

    Hi János,

    First of all, thanks for providing such an amazing resource!

    Thanks to the information on your blog and lensrental’s, I’ve been able to restore the USM focus motor operation on a Canon EF 24-70mm f/2.8L USM Mark I.

    My problem is adjusting the infinity focus position. At 24mm the focus ring reaches the hard-stop while the peak focus still seems to be at perhaps 20 metres or so. The 70mm position is good, with infinity focus being reached just before the end of travel so it will focus slightly beyond infinity.

    I don’t recall seeing any washers/spacers on the mounting bayonet that I could remove.

    I didn’t alter the rear lens group but that group comes off with the zoom ring assembly so that may have messed things up – also the lens has definitely been worked on previously by… well, probably not canon, I am guessing.

    I did realign the front element for centering and tilt, the ramps ended up in the same position as original (I adjusted for best apparent sharpness wide and tele, fairly unscientifically). The tilt adjustment was changed to maximise symmetry of blur/chroma fringing on a high-contrast target.

    Any tips on fine-tuning the infinity focus on this lens, and if perhaps I need to look at the centering of the rear group? I need to strip it down again to increase stator tension on the USM anyway so might as well “dot the i’s and cross the t’s”, as they say.

    I’ve been messing around with electronics my whole life and I have to say, lens surgery must be on a par with bomb disposal for high-stress work (at least for L series glass, anyway!)

    • canonrepair says:

      the problems is, that case somebody has missed some parts (washers, spacers etc) – will be hard to find all te positions.
      Let we suppose, that the problem is only with a replaced bayonett. In that case would help to find an an another, thinner bayonett (any other canon lens, just for testing. Case this helps, you can work the ooriginal bayonett on a lathe thinner. (One of the important tools, which I have: a small, 40 years old russian lathe, and a small chinese milling machine.

      • agittins says:

        Thank you very much for your response. When you mentioned the bayonet thickness I did some further searching and as you say, it seems that wide-open infinity focus is set by the factory’s choice of bayonet thickness.

        I think I will not attempt altering the existing bayonet as I don’t have the tools or expertise to do so while still ensuring it is parallel. When I open it back up for the USM tweaks I will see if perhaps I have assembled it in a way that may have added any slight thickness and also test on another body to see if it might just be an issue of compounding tolerances.

        After that, I think I should perhaps go outside and enjoy it and stop squinting at pixels! I think the centering seems fairly good at least.

        Thanks again for your help!

        (feel free to delete my duplicate comment, the wordpress account login worked *after* it posted my comment so I could not see my non-account comment was in moderation).

  10. Hi János,

    First of all, thanks for providing such an amazing resource!

    Thanks to the information on your blog and lensrental’s, I’ve been able to restore the USM focus motor operation on a Canon EF 24-70mm f/2.8L USM Mark I.

    My problem is adjusting the infinity focus position. At 24mm the focus ring reaches the hard-stop while the peak focus still seems to be at perhaps 20 metres or so. The 70mm position is good, with infinity focus being reached just before the end of travel so it will focus slightly beyond infinity.

    I don’t recall seeing any washers/spacers on the mounting bayonet that I could remove.

    I didn’t alter the rear lens group but that group comes off with the zoom ring assembly so that may have messed things up – also the lens seems to have been worked on previously by… well, probably not canon, I am guessing.

    I did realign the front element for centering and tilt, the ramps ended up in the same position as originally (I adjusted for best apparent sharpness, fairly unscientifically). The tilt adjustment was changed to maximise symmetry of blur/chroma fringing on a high-contrast target.

    Any tips on fine-tuning the infinity focus on this lens, and if perhaps I need to look at the centering of the rear group? I need to strip it down again to increase stator tension on the USM anyway so might as well “dot the i’s and cross the t’s”, as they say.

    I’ve been messing around with electronics my whole life and I have to say, lens surgery must be on a par with bomb disposal for high-stress work (at least for L series glass, anyway!)

  11. John says:

    whats your email, i have some lenses that need repair and i would like for you to give me a quote.
    Thank you

  12. Deividas Rainys says:

    I have a 1300D which had corrosion on the back of the power board due to some water ingress. I cleaned it with 99.99% IPA, however it still did not work. I think I saw perhaps one or two traces that may have been corroded through.

    Is it likely that a faulty power board could damage the rest of the camera or should the issue be isolated to this location do you think? I also accidentally shorted the flash capacitor to the body when discharging it hopefully this hasn’t caused any further damage.

    I have ordered a replacement power board in the meantime. Hopefully this fixes the issue!

    • canonrepair says:

      would be very difficult to give a GENERAL solution – without not even seeing it.
      50% probability, that the camera will work. Yes or no.
      Nobody could tell you a real answer. Just try it.

      • Deividas says:

        Thanks for the quick reply. Guess it’s just a waiting game till the replacement board arrives! I’ll let you know what happens ☺️

      • Deividas says:

        Part arrived today, replaced it and all seems to work great! Obviously the original power board had more corrosion than I had thought and cleaning wasn’t enough.

  13. rich139 says:

    Canon 500mm F4 Fungus inside front element.

    Hi there, I was wondering if you have any experience working on Canon 500mm F4 IS? I appear to have a small amount of fungus just inside the front element, and cannot find anyone locally to repair it. Do you know the repair would be possible?

    Thank you,

    • canonrepair says:

      I am sure, that SOME KIND OF REPAIR is possible. In the worst case disassembling the element, polishing it (possibly eliminating the anti reflection coating), and mounting back. Where are You from? EU?

  14. Mark says:


    I just read your awesome post about the coaxiality adjustment of a 24-105mm L after opening the assembly to replace the aperture flex.

    I’m currently working on a 17-55mm IS with a broken aperture flex. It’s aperture unit, consisting of two lens elements with the aperture in between, also has to be opened in order to change the aperture flex. Is there any danger to lose coaxiality if you open the aperture unit and put it back together after replacing the flex cable?


    • canonrepair says:

      Dear Mark, i am happy to hear that you like it.
      Not any lens has adjustable lens elements. As I remember, the 17-55 is more like the 17-85, so has not this possibility. The problem is, that I repair in a very random schedule, and I always decide what to to when I see it opened on the desk.
      Case 1755 has the excentric pins, than is adjustable.
      With the “symmetrical chromatic aberration” method (to find the best coaxiality) you can work by ANY lens.
      Where are you from?

      • Mark says:


        thanks a lot. You’re right, the 17-55mm doesn’t have pins. However, the 18-55mm kit also has an assembly where you have to separate two lens elements in order to get to the aperture flex. If you put it back together coxialty is lost. That’s why I was afraid that it could be similar with the 17-55nnm.

        All the best from the UK

      • canonrepair says:

        you are right. that is the othe, a little bit primitive method – but used by the 70-200 f2.8 IS II too (!). Just bigger holes, and ater adjustment you have to tighten the screws.
        sometimes helps to scrath 3 marks on the two parts with a sharp knife, to position it back as it was.

  15. Lee says:

    USM issue on 24-70. lens, Twice I have fixed it by stripping, cleaning the usm parts and tensioning the spring. And cleaned the optical sensor strip. Mechanically both the manual and auto focus parts of the usm motor move the focus elements when turned by hand during the fix. After some time the auto focus Stops working, I can only hear a very tiny audible click from the usm motor but no focus activity.

    A question, is the usm stator and rotor, are they supposed to stick together in any part of its activity? Because when I first separate them they are kind of stuck together slightly. Or if I clean them and rotate them together Against each other I can create what feels like an electromagnetic stickiness. Is there supposed to be this magnetic type activity? And what is my best solution?

    • canonrepair says:

      the two halves of the USM are “sticking ” together exclusively by the perfect plane surfaces – practically the atomic forces from the two metal rings.
      This means, they have to be polished perfectly plane like a mirror.
      This is a part of USM refurbishing which I do often.

  16. Jiří Dejmek says:

    Hello I am trying to solve unsolveable puzzle. I have two lenses 17-85 and 70-300 DO with similar symptoms and no way to go now…
    Trying to fix an old 17-85 that refuses to open its aperture, after its change fully opened just closes during a testin and never opens againd.
    Tested three diferrent motherboards fully functional… no luck
    Tested three diferrent aperture assemblies… no luck (all tested on another lens and worked well)
    Tested the aperture in the lens connected to another fully functional lens… worked and fully opened instantly.
    I have absolutely NO IDEA what could be wrong… last part which was not changed is a USM motor part including focal distance register and its brush but ive completely inspected that and cannot see parallel between that and malfunctioning aperture assy hence the camera reflects minimal aperture value right according to actual focal distance.
    Has anybody solved this similar mystery? HOW?

    • canonrepair says:

      look, the aperture has a position (a ZERO position) sensor. Case is not in ZERO position, the electronic board MUST close it. It is a stepper motor, by the way.
      Case the OPEN information was there, the stepper sholuld rotate. You can check it: has 4 pins, 2 + 2 are connected through the coils, a few ohm resistance.
      It can be a problem with the cable too – case it is broken for ex, but not fully broken. Check it!

      • Jiří Dejmek says:

        Well that is the problem, when I take otherwise perfectly functional aperture outside body of the lens it behaves same… even after motherboard swap of motherboard from another functional lens!
        When I conected aperture cable to another lens: ,mounted the camera and tried it it immediately returned to fully open positon still inside its lens.
        It must be possesed or cursed… 😛
        Ive bought it with this problem thinking “easy-fix” but it had new, fully functional mechanism inside. After swaping marathon of parts from another lenses I am completely out of ideas. \o/

  17. David says:

    Hi Janosz,

    Your blog has helped me out massively over the last couple of years, thank you!
    I’ve been a lurker but this is my first time asking a question.

    I currently have a Canon 600D which is behaving very odd! The photos taken seem to be hit and miss, sometimes they come out great but then they gradually start changing colour with strong purples, greens and reds.
    I initially thought it was an issue with the sensor so replaced that to no avail. Before I start changing other things like the main board, have you or anyone else reading, come across this issue before?

    Many thanks

  18. Achmed Azizie B Marzuki says:

    Hello Sir,

    thanks for compiling this valuable step by step guides, I’m planning to replace my shutter assembly for my Canon 50D, I found quite a few sold in ebay, my concern is, how do I know which one is genuine?

    Appreciate your advice on this.

    Achmed Azizie B Marzuki

  19. Raylon Ironside says:

    Hey I got a question, where can I find the pcb schematics for a 77D? Im trying to replace the capacitor locate right below the memory card reader as well as the reader itself.

  20. Jiří Dejmek says:

    Hello Janosz, your blog is heavy inspiration for me from start to now on.
    Few weeks ago I acquired 70-300 “DO” IS USM after drowning in the pool, after quick inspection Ive realised its is fully working (even IS!!!) and its only problem was a lot of dried water drops in ALL of optics elements so contrast and quality was not there.
    Then Ive cleaned first element and stabilizer front… still some dried drops in other glass elements with one HUGE drop right in the middle of one. So ive proceeded to complete disassembly of the lens including its “heart”. Ive quite precious with marking positions of all the excenttric washers alhough because it is quite complicated glass, I maybe rotated one or two elements and I dont know relative position of front lens barrel with diffractive lens to lens “heart”.
    Do you have some methods to fine-tune lens alignment? Lens needs to be partially disassembled for it and I have absolutely no clue how to do it.
    Any way Im not counting with much sharpness at all, but trying to save it from making a pen-holder or decoration from it. 😉

    • canonrepair says:

      Hi Jiří, there is only one method: if you separate the functional groups, you bring them into the best position, after which you mount them, and do it again for the whole lens.
      I made now for myself a bench to set the coaxiality of alens – but I never tried to make a COMPLETE lens from 0.
      Not too easy, as You should have a fixture for each element etc.

      The best would be to get red of another lens, and to mount thye elements of yours in it one by one,

      • Jiří Dejmek says:

        Thank you, for reply…. Ive managed to completely lost photo documentation of disassembly so after few weeks of all elements lying on my desk Ive managed to make it somehow complete and sort off working.
        Unfortunately Ive been too rough during reassembly as frustrating it was… some parts needed toput in and out for 10 times so stabilizer is no longer working (and it rattles even with lens OFF).
        Next bad thing is aperture was able only to close itself but cannot reopen. Is possible it was caused by motherboard bath in IPA to remove all water debris?
        I have same problem with one 17-85 where even complete aperture assembly change did not worked and behaved actually same but not sure what is the cause.
        Optical quality before aperture closing was surprisingly good but Im keeping this tinkering around for long winter nights.

        At least I have a green striped lens in the collection. 🙂

        Have a good light!

      • canonrepair says:

        Next time start with a more simple lens 🙂
        Good luck!

      • Jiří Dejmek says:

        Well Im quite succesfull in lens fixing and cleaning…but the 70-300 DO was a nightmare for me. Ive finally managed to put the lens together the right way on the 5th go. And it worked with quite acceptable quality BUT: Mostlikely after cleaning electronics board from chlorine debris in ultrasonic cleaner and isopropanol it refuses to activate IS and at the worst: Once I closed aperture to F11 it wont re-open again.
        I have similar issue with one 17-85 and was never able to solve it out, so for now I have nice green-striped brick.

  21. Josh Harris says:


    I’m currently working on my Canon 70-200mm f4 IS USM. The focus gets stuck (in MF & AF) so the lens won’t focus below 2 meters. I disassembled the lens, marked the positions of all the excentric rollers and isolated the Issue to the main barrel that houses the lens groups in the front. Moving the focus coupling key I can feel a slight resistance towards the near end of the focus lens movement. Anyways, I found out that the excentric rollers of the 2G lens element can be ordered in three different sizes. Do you know (when I pick a smaller size of the rollers) if the resistance will go away? Did you ever come across such a case?


    • canonrepair says:

      “…Do you know (when I pick a smaller size of the rollers) if the resistance will go away?…”
      I am afraid, not.
      If the rollers dimension is not good, would not be good for the whole length.
      unfortunatelly can be that you have a cracked or deformed barrel.

      • Josh Harris says:

        Thank you for your reply. I see. Anyway, since the rollers are pretty cheap I think I’ll give it a try. I guess if the barrel is deformed, I would have to change the whole unit which is… pricey – and I guess the following adjustments are pretty much impossible to do at home. Do you know if its possible to get the barrel straight again or is that a lost cause?

  22. Rolf Wollesen says:

    Hello. I have a Canon 24-105mm v1 where I have replaced the aperture unit. But the lens is very soft when taking images at aperture F4-F5.6. It gets even worse when zooming in. At aperture F7.1-F22 it is razor sharp again… Do you have an idea about what could be wrong?

    Kind regards

    • Tom says:

      Hello Rolf, i´m sorry to say that… if you change this group you have to align the optic. There are excentric collars which have to aligned new and the group itself has excentic bolts too. If you don´t know that, you can´t see them from outside… Send it to Canon or another company like Maerz or buy a new one.

    • canonrepair says:

      Canon 24-105mm HAVE TO BE ADJUSTED after this operation.
      I could do it too, unfortunatelly the cost is approx similar to a flex cable replacement, as i should disassemble it first (and I neve do adjustment without checking of the rest), and of course the post is expensiv too.
      Or You can do it by yourself, if you read it on my blog.

      Adjusting the coaxiality of the 3. lens group in an EF 24-105 IS USM lens

      • Rolf Wollesen says:

        Thanks for getting back to me. I will try to adjust it myself using your guide.

  23. Frank says:

    My Canon Rebel T3 is giving Error 30 after every shot, even though it seems to work perfectly otherwise. Even high shutter speed photos are fine. Pressing the shutter release when the error shows gets the camera working again – no need to remove battery etc.
    LiveMode and video work fine, the error occurs when the mirror drops.

    I’ve tried a quick squirt of cleaner onto the phase sensor, but that didn’t help, so I’m now guessing its the mirror sensor? Does that sensor detect the mirror being “up” or “down” ?

    • canonrepair says:

      “Does that sensor detect the mirror being “up” or “down” ” the sensor knows only the position of the moving cam – so it is not sure, that the mirror makes in reallity the same moving.

    • Tom says:

      I would have a look here to the motor. Some of them have internal problems. The second, and i´m not shure if the T3 will have one, would be a deeper look to the gear with the position contacts. In some cases they will have a bad connection (internal). The third could be the shutter itself/ the loading mechanism with the sensors for the shutter blades.

  24. Andreah says:

    Canon 200D
    I received my camera as a gift for Christmas in 2019. Lately I’ve had a error 70. Is there any way to repair, or do I have to get a new pcb?

    • canonrepair says:

      Unforutnatelly I dont’t think that anybody could answer this generally, just from a fault code.

      • Tom says:

        Hmm, i´ve had two of them. They have a “one in all” mainboard. If the cam hasn´t got wet, there are two possible errors: one is the very cheap made shutter and the second is the flash unit with it´s “magnetic drive”. But be very very careful: the cable from the screen to the mainboard is very short and extremely sensitive. Once damaged you have to buy the completely back.

  25. Francis Gimenez says:


    I bought a second hand canon 17-40mm for my 6d mark iI, while AF seems to work fine it is giving me wrong focal length exif information. 17mm on the lens will display as 19mm on the exif of the images while 20mm on the lens shows 21mm. This happens ( add 1 or 2 mm) to the other focal length markings on the lens except when turn the lens all the way to 40mm. I searched online and found a few forums about this specific lens having this minor problem

    • canonrepair says:

      on the side of the zoom barrel must be a metal “brush”, which reads the strips of the flex, which has a 5 (6?) bit coding of the focal distance. If you loosen the screw, you can move it, and the focal information will change.

  26. Cedric says:

    I tried to repair the eyecup lens of my 50D today, while removing the top case (with the rotating selector), the flash PCB touched the metallic chassis and violently discharged on it. I was not too worried about that (just shorted the capacitor) but when I reassembled it, it did not power on….
    I tested to check voltage on the mainboard, i can find 5V, 3.3V. Do you know if there are fuses to check and where ? I ordered a used mainboard, waiting for it.
    Is there a service manual with schematics available ?
    Best regards.

  27. stijncuypers says:


    I have a dead canon 5D mark ii, no lights or so blinking anymore. I tried already to change the usual suspects (batteries and so on) without succes. I even opened the body to inspect if I could find a default, but at first glance it still seems to be ok. However I read about a faulty resistor on the DC/DC power board. How can I inspect this part and how can I be sure that this is the only default? Are there other things I should look into before ordering a spare DC/DC board?

    Thanks already

  28. Stephan Paulicks says:

    Canon EOS 70D
    Hello, have a question regarding my 70D. After a longer video session my camera does not start anymore. Tried the usual things: two different batteries, dc adapter, micro-switches. Nothing happens, but: if I connect the external dc power while the battery dummy in the camera and the power switch is set to ON, the “empty battery symbol” in the camera blinks. If I do anything like switching on and of or open the battery slot, it disappears. This is the only life sign.
    I will be able to open the camera, measure voltage and soldering is no problem.
    My question is: is there anything I could measure or check to find the defective before purchasing expensive spare parts like main board or dc/dc board?
    Thanks a lot! Előre is köszönöm, Stephan.

    • canonrepair says:

      unfortunately no ideea.
      this is why i have donors for parts. and exactly for a 70d i have a dead camera…

      • Tom says:

        The 60/70D series is horrible (sorry Canon..). Now it looks like the DC/DC is dead. And there is a power ic M04 on the motherboard. Both is available on Ebay or China market. You should have a look at them.

      • Stephan Paulicks says:

        Thank you for your hints. Will try to get spare parts on eBay.

    • NISSIM BARKI says:

      Same problem with my Canon 70D.
      Finally i change the mother board. This is the problem when you use a longer video session.

      • James says:

        Did anyone find any luck after replacing the power ic M04 on the motherboard???
        I am facing the same problem.

  29. Dave says:

    Canon 7d
    I have a few faulty flash boards for the 7d all show err 40 when fitted to a camera
    I know the rest of the camera is ok, If I fit a different flash board it works fine.
    My question is can I repair the faulty boards?
    I am fairly competent with electronics and soldering ect
    I know its easy to just replace the board but it would be nice to learn what blows on these boards
    Not sure where to start with testing them so any help would be great.

    • canonrepair says:

      on that boards you have some active elements, for ex a specialised dc-dc converter.
      if you can replace that.

      • Hola desde Venezuela. Tengo una Canon 5D Mark iii que no enciende por nada. La cámara no sufrió golpes ni nada similar que pudiera afectarla, simplemente un día dejó de disparar y no encendió más. He intentado varias cosas que he visto en Youtube (pestillo en la tapa de la batería, carga de batería, pestillo en la unidad SD), encendido con y sin CF, nada que enciende. Qué debo hacer antes de desarmar y por dónde debo empezar. No tengo conocimiento de electrónica y solo lo que veo en los videos que reparan algunas piezas de este equipo. AYUDA.

      • canonrepair says:

        google translation:
        “Hello from Venezuela. I have a Canon 5D Mark iii that won’t turn on for nothing. The camera did not suffer blows or anything similar that could affect it, it simply stopped shooting one day and did not turn on again. I have tried various things that I have seen on Youtube (latch on battery cover, battery charge, latch on SD drive), turned on with and without CF, nothing that turns on. What should I do before disassembling and where should I start. I have no knowledge of electronics and only what I see in the videos that repair some pieces of this equipment. HELP.”

        I wd say, disassemble it, and search for loosen flex cables, and signs of water intrusion.
        If you have for ex a small corrosion rest on a flex, can causea a short of 10-20 kohm – and this is enough not to let the camera to switch on…..

      • Mil gracias por su respuesta. Voy a intentar abrirla y le estaré notificando, le mantendré informado, su ayuda es muy útil y su blog es lo mejor de lo mejor que he podido encontrar en internet.

        El vie, 18 dic 2020 a las 18:02, DIGITAL CANON repair blog () escribió:

        > canonrepair commented: “google translation: “Hello from Venezuela. I have > a Canon 5D Mark iii that won’t turn on for nothing. The camera did not > suffer blows or anything similar that could affect it, it simply stopped > shooting one day and did not turn on again. I have tried vari” >

    • Tom says:

      You will find the parts at china sources but you can´t repace then without having the right equipment. Desoldering: pre-heater and a regulated air-gun rework station. Cleaning the surface and renewing the soldering on that pins (you have pins around the chip and a quad cooling zone which have to be soldered too. SMD-flux. Then replacing the chip. Solder the chip in the same way above mentioned. And be careful with the parts which are near to the chip. They are “free” in that moment you can lift up the old chip….

  30. Michael says:

    Hi what a wonderful blog,

    I do wish I’d thought to search a bit harder for it before today but that is ok!
    I bought a 5d mk ii with error 30, usb not working and a dodgy top wheel (it was just slipping and needed adjusting with the indent spring).
    I opened it up expecting to find a broken usb port, but it looked fine and tested good on a multimeter.
    So I continued on to the shutter (without taking any precise sensor measurements…Oops.)
    The shutter motor winds but the curtains never release (both) I had a look and they release properly when trigged manually.
    The camera is all back together and still showing error 30 and I plan to buy a shutter on Ebay and see if that fixes the problem. Is it worth taking it apart again and taking the shutter actuators apart like you show in a blog post? Both coils had a similar resistance of ~1.5 Ohms so I didn’t dig further.
    I’m worried that there might be a problem elsewhere causing the shutter not to fire.
    Would love for any suggestions.
    Take care,

    • canonrepair says:

      this type of shutter has a mechanical cocking, and electromagnetic release. The motor HAS TO STOP in an exact defined position after cocking. This is sensed by a mechanical contact a printed circuit and a brush – that could be damaged or just dirty.
      By the way, there is an another thing too – the curtains have position sensors too. Case the end-brakes are too strong or too loose, after activating the curtains the curtain position will be not accepted. Here would be a great help a good working shutter to check the brakes strength.

      • Erwin says:

        Hi János,
        do you have information on the electrical design of the shutter sensors? I ask because I’m trying to emulate the signals of a 6D shutter and there are 3 pins which I do not fully understand. And I wouldn’t like to completely disassemble the camera before I’m sure that I can replace the shutter by an emulator.

      • canonrepair says:

        I think there are some simple infrared-opto couplers. you can measure out with a multimeter. 1 pin is common, one is power for the led, and the third is the signal. but they need probably a resistor on the signal, as the phototransistor puts the pin on gnd when gets light – so in fact, switches on current on that resistor. I suppose.

    • canonrepair says:

      But with the unmeasured cmos position….

      • Michael says:

        So for some reason disassembling the camera revived the shutter slightly, and the CMOS position that I carefully did based on turns and position markings on the screws only messed up the autofocus slightly (adjusted with magic lantern between 30 and 70 to fix depending on lens). I’m sure it’s still quite out in the other Axis but I don’t have a way of measuring that.
        The shutter error seems to return if I don’t use the camera regularly or don’t leave it overnight in the sensor cleaning mode (shutter open with sensor exposed). Maybe those curtain positions sensors are the cause…
        The spare shutter is sitting on my desk threatening to be put in if and when it fails again and once that happens I’ll probably get canon to align it and calibrate the shutter since the quote was reasonable.
        Seems to be something mechanically misbehaving in the shutter since it only had 35k clicks when this started.
        Thanks for your advice

      • Tom says:

        ?? use a new shutter. You can repair the curtains, but if there is something mechanical, which causes a delay in timimg, you will always have this probs. May be rust, may be the dampers. For re-adjusting: i hope, you haven´t done anything with the shutterbox and the af sensor. If there are still aligned, you have to use a good optic with a good sharpness in the edges. Connect your camera with the computer and use canon´s remote program. Af to a flat testing chart. Switch to MF and switch to lifeview. Then you have to adjust the 3 screws till you have a sharp picture. It sound´s easy, but it is very tricky and costs time…

      • canonrepair says:

        there is probably a problem with the end position brake, which is a friction brake. you could try to compare its action (when ther are both on the desk), to see if there is any difference between the braking force .
        the working a few times after a few hours of pause could be caused by this.

  31. Dani says:


    Got a 5D mk1 with bent and shorted pins in CF slot, and the camera would not turn on. Fixed the CF slot and verified there are no shorts.

    Got a short in F101 fuse on DCDC board, replaced that. All other fuses are good and receive power. Tried to connect the DCDC board to the battery, but I don’t get any power on the board output. Is that normal? Do I have to send some signal to the DCDC board to turn on? If yes, how do I do it?

    Which board supplies power to the circuitry that is connected to the switch and powers on the camera – DCDC or LPU?

    Thank you!

    • Dani says:

      I meant, got a blown F101 fuse. It’s late…

      Checked the DCDC board – no shorts on inputs or outputs. Checked the D_PCB, no shorts. So, the D_PCB is not killing the DCDC board.

      • canonrepair says:

        5d mk1 is very sensitive.
        can be a problem on the main board too.
        or a contact problem on a flex cable.
        dc-dc board is enabled by the main board, as i know.

  32. Tom says:

    ERR06 – sensor cleaning is not possible…. I´m looking for the possible reason of the “death of this unit”. In many cases i can read “canon has changed the whole sensor unit”- why, it´s only the first glass of the sensor and it´s possible to change it. Others say: sensor and the unit is a combination, may be there is any setup/frequency data stored on the sensor´s pcb. Next one is the driver board of this unit – a possible fault too. But what if… when you can see the glass vibrating and the shutter moving? Where could be then the error? Mainboard? Or mainboard setting? So, have anyone of you solved this common error? If the Mainboard has been changed.. is there any setting necessary? Your experience… please make a note

    • Erwin says:

      Changing the first glass of the sensor is quite easy. A bit more difficult is to keep dust away from the gap between 1st and 2nd glass. I guess this might be the reason why professional repair service doesn’t over this kind of repair.
      The main pcb holds lot of information about the sensor for e.g. hot & dead pixel supression. There is special software to configure it after exchanges.

      • canonrepair says:

        I have done many times the disassembling/assembling of the filter. even to get out dust FROM THE FACTORY. (has never been disassembled before.
        it is not impossible to do without getting dust between the glasses.

  33. Eric says:

    Hello, guys! I learn a lot on this site about Canon DLSR. Thanks for that.
    I asking for Help for my Canon 5D Mark II, i have an err70 for few weeks now and i trying to repair
    the DC board.
    Can you help me identify those 2 components that are shorted ?
    1. ( )
    2. ( )
    And i have a question:
    For testing the several fuse on this board, you must first desolder them ?
    Thanks !

  34. emapro96 says:

    Good evening,
    I recently I bought a Canon 5D Mk II on catawiki, the seller sold it as for parts. The camera is fully working except the mirror: when I press the botton for take a picture, it won’t go up but I can hear the mirror engine working. I haven’t yet taken it apart, but I thought it could be a gear problem between the engine and the mirror it self. For this reason I start looking for the service manual before open it, but without any luck. (I attach a video:!AmLSrBGTcCV8iVLe0hPtiJqpPyuB?e=ZaG9Xe) Has anyone had the same problem or could help me?

    • canonrepair says:

      I ont have a service manual, and I think that the service manual would not help You – you will have probably a broken gear or any othe rpart.
      You have to disassemble it, and to understand how it works.

      • emapro96 says:

        Yes, I will! there’s a site where I can find some camera plastic gear?

      • Tom says:

        Hi, i think you won´t get a service manual. And if, you will not find there anythin useful in this case cause Canon replaces whole groups. It´s very very seldom, that a gear breaks. A commom problem will be the motor of this gear; the contact wheel for mirror position or a spring (missing/broken). If you have dismateled it and removed the gear part, the mirror should be moving freely. You can replace the complete mirror box, but then you have to align a lot of things- and some of them you will need a specific software.

    • emapro96 says:

      Ook thank you so much! I will check for the motor and hope very strongly this will be the problem! In other case I’ll probably continue to use it in this condition! :))

  35. Michael Trustrup says:

    I come to you in hope of adjusting my lens.
    It is a 70-200 F4 IS USM, that I bought very cheap because the rest housing was cracked.
    I bought a new housing and changed it, but stupid me, loosened the screws for the rear lens pack during disassembly. There are 3 holes with 4 eccentric screws in them. I have managed to get the lens fairly sharp (85%) again, using a ISO 12233 chart. But I have a chromatic aberration, particularly on the right side.
    How to get it 100% sharp, and get rid of the chromatic aberration?
    I tried your method with a light and a black triangle 1x1x1cm at 1m distance at 200mm zoom. But I can’t seem to notice any difference when I adjust the lens at all.
    I hope you can help. Sending it to Canon for adjustment cost as much as a used lens.

    • canonrepair says:

      something is not ok there. as I remeber, they should be 2 x 3 = 6 oval holes, and 2 x 3 rollers, from which 2×2 are excentric and 2×1 are cilindrical. From the 2 x 3 oval holes 3 are axial and 3 are tangential – so you can adjust the tilt and the shift separately of that element. In your case the tilt is the problem, so the oval holes which are tangential.

  36. Benjamin says:

    Hi János,
    Thanks for all the information on this site – it’s a really useful reference for amatuer repairers.
    I’m trying to repair a Canon 5D mark I that wouldn’t power on. After some tinkering the top LCD and buttons now work, but nothing else. The microswitches work as expected, and I’ve tested the two fuses on the LPU PCB and four fuses on the DC/DC PCB and they’re fine.
    What I’ve read on the internet indicates that the problem is likely to be either the DC/DC PCB (which would be a fairly easy replacement), or the digital PCB (which I presume would not be viable because I can’t recalibrate the camera). Do you have any suggestions for working out which PCB is at fault?
    Thanks in advance.

    • canonrepair says:

      unfortunatelly I see no other choice, than a donor camera. You could measure the voltage levels on the DC DC PCB – but I think has more sense to get rid of another working camera.

      • Benjamin says:

        Thanks for your comment. I will try to get a donor camera and hope that the broken camera won’t damage parts from the donor (I presume that it’s safer to take a part out of the donor to try in the broken camera than it is to try a suspect part from the broken camera in the donor camera).
        I was going to make a very small donation but your donation link is broken!

  37. Nagy Bence says:

    Kedves Ruzsa János,

    Elnézést kérek, hogy itt írok önnek de sajnos a oldalt nem érem el.

    Segítséget szeretnék kérni a 450D-m hez. Eggyik fotózás közben adódott a probléma mert csak a képek “felét” készitettem el.
    Szerintem a zár adta meg magát. ( )
    Esetleg tud segíteni nekem ezen a problémán?

    Válaszát elöre is köszönöm

    Nagy Bence

    • canonrepair says:

      a magyar oldalt sajnos feltörték, dolgozunk rajta.
      ezen a gépen zárat kell cserélni. valószínűleg tudok bele keresni egy bontottat, és akkor 25000 ft.
      vagy márkaszerviz, ami 35000 ft.
      csak akkor érdemes, ha a zár nem karcolta meg az érzékelőt.

      • Nagy Bence says:

        Először is szeretném megköszönni a gyors választ,
        másrész szeretnék élni az ön által ajánlot lehetöséggel. Ennek részleteit van lehetöség emailben megbeszélni?(pl: Hol tudom át adni a gépet)

        Válaszát elöre is köszönöm

        Nagy Bence

  38. Laszlo Merhay says:

    Kedves János,

    full spectrum konverzióra lennem szükségem, az ideális vázat még keresem hozzá, de valószínűleg 6D, vagy 7D lesz. Ezt tudod vállalni?


    • canonrepair says:

      Én biztosan a 7d vázat választanám. Sokkal strapabíróbb, a 6d az egy elég undorító termék.

      • Laszlo Merhay says:

        Köszönöm! Igen, nekem sem szimpatikus a 6D, viszont full frame… ezzel együtt is a 7D, esetleg 70D felé hajlok. Tudsz esetleg mailben adni elérhetőséget, hogy megbeszéljük a továbbiakat?

  39. dyt811 says:

    Dear Ruzsa János,

    Thank you for the awesome blog! I really wish I had read your 2017 entry on Canon EOS 5D MKII Error 30 issue before I took mine apart (and successfully put back together after replacing original shutter with ebay shutter module replacement part myself.). Everything (aside from the flange adjustment issue I absolutely introduced by not measuring before dismounting CMOS sensor…) worked as intended except the Error 30 remains. The previous shutter died at 45K ish according to MagicLantern and no physical abnormalities. These coupled with the fact the new replacement shutter did not make any differences on Error 30 lead me to conclude it might be a faulty board somewhere… I was wondering if you have any insight on which board or what to check next? I do not have SPT software so cannot really check the message easily. Any tips, tricks would be greatly appreciated.

    I documented some of my steps and status here:

    • canonrepair says:

      Hi, unfrtunatelly, will be not easy without a donor.
      Check the phase sensor (for shutter and mirror both!), check ALL the fuses on the DC board and as I remember, there are some on a side board too.
      try to turn the motor to an intermediate position (half open shutter). After reconnecting, the main board should move it to the zero position. Will do it or not? Do the same with the mirror motor too.

      • Tom says:

        ERR30 is a very common error for the 5D2/3 series. Yes, the first “look” will go to the shutter. In most cases the initial position will fail (broken blades or wrong manufactured china products!). Many of these china reproductions are old shutters with new blades. Pls be careful and have a look to your old one. I try to use to old one cause the timing delay is after reassembling in mose cases ok. The second one is the initial position of the mirror. First thing: have a look at the little motors on both sides (on is mounted on the shutter board one on the shutter box. You remember: Canon´s problem with defective magnets inside?. The unit at the mirror box has a litte gear with internal contacts to give the mobo information about the mirror pos. Gear & contacts ok? I think, it´s not a problem of the mobo, i think it´s a timining problem. But if you have taken out the sensor without measuring the distance… the you should stop here. You will need a specialist for adjustment of AF-sensor to photo-sensor. In all cases: leave the AF-sensor unattached! It´s a little better for re-adjustment, if one thing is correct. Regards

  40. I know it’s a bit old but I have really looked after it and it looks like new though it is well used.
    It won’t power up, I have seen videos about the microswitches and changing lenses and I am in the process of trying these though so far no success. I read that there is a fuse on the DC/DC board and would like to know how to safely access this so I can change the fuse, hopefully there is a spare as well. Also I understand that the flash capacitor is in this area so some safety tips would be most helpful, Kind regards Nic ;o)

    Great blog wow what a contribution!

  41. Eric Ryan says:


    I have a Canon 60D that is getting a flashing battery Icon regardless if I use a new battery. Once I turn it on and it starts flashing it will keep flashing even when the camera is set to off. I’m in doubt if this is related to the DC/DC board or the logic board. I do have some DSLR repair experience but have never stumbled across this.

    Any help is deeply appreciated.

    • canonrepair says:

      i think 99% is the dc/dc board.
      if you have more time than money, you can try to replace the maxell IC on it, search it on ebay. or you can order the board, case is that the problem, keep it, case not, you can resell it anytime.

      • Thomas Loebl says:

        I have had a 60D with the same error. I have replaced the CG2-2860 bottom pcb and the CG2-2862 dc/dc. But i couldn´t solve the problem. Sorry when i say that: the 60D/70D cam is internally like a “consumer class” cam; simply worse and i wouldn´t spend time and money in that body.

      • canonrepair says:

        yes, the 60d is a controversial body.
        much too sensitive, and has no possibility for lens AF adjustment.

      • Thomas Loebl says:

        I have see a lot of died bodys only by a few drops of water at the back… if you dismantle one of both bodys you will find… a not overlapping plastic case, badly sealed buttons, a very very cheap shuttergroup and all of the essential electronics on the main pcb. The have splitted the regulating dc to dc/dc and main pcb. 70D is the same with a better sensor. May be caused by the consumers the 80d is completely different and built like a 50D (with plastics). By that issue i can only recommend to throw it in E-bay for spares…

    • Eric Ryan says:

      I ordered and replaced the DC/DC board. Seems to be working fine so far. Thanks a million!

    • Jiří Dejmek says:

      I have same behavior with 7D, my ivestigation excluded missing screws… and now I am hesitating between DC/DC board and bottom flash board. What is your tips guys?

  42. Erwin Lotter says:

    Canon 6D focusing issue

    Hi, after I dropped my 6D body it cannot find the focus anymore: scans forth and back through the whole range and stops then. This is independent of light and lens, but happens only if a single spot is selected. In automatic mode with several spots used, focusing still works (fine and fast).
    Is there a chance to repair at home?


    • Tom says:

      Hello Erwin, i think that in live view everything is correct. I think the AF-sensor is misaligned, maybe the clue has come off. The other possibility is a damage to the sensor or/and the flex cable.This comes a littel closer cause you´ve said that it will focus correct with all AF-points “on”. But there is another possibility… does your light metering function act correct?. In many cases -after been knocked- the glue from the LM Sensor will come off and now it is “too dark” to find an object with the central AF point.
      For all that you have to dismantle your 6D. Under the top unit (small display) you will find between the pentaprism and the eyeview the sensor on the top with two glue points. If it is loose, that it´s deadjusted. The AF sensor part is at the front side below. Front and Base has to be removed. The metering can be adjusted by yourself; the AF not.

      • Erwin Lotter says:

        Hello Tom,
        thanks for your hints. My impression was that light metering works still fine, but I will re-check this.
        Such a kind of failure could explain why the focus is found when at least two or three of the AF points are used while it is never found if only (any) single one is in use. If the AF sensor was missaligned I wouldn’t expect to get a proper focus anyhow..

      • Tom says:

        Yes, you´re right. Check the AF sensor alignment with a plain test sheet and use one dot in all four edges.. To check the light meter switch it over to the central point only. Then take a small led or point source and center this “light source” in the middle. You should have there a very short time. If you begin to move it beside the center… you shoult get lower rates. If you have a higher rate beside the middle… you´ve found your candidate. I´ve had such an issue with a 5D3 🙂

      • Erwin Lotter says:

        Hi Tom,
        following your advice I verified that light metering properly identifies a bright spot in the center and shows a fast decline aside. Next I checked each of the AF points and found this pattern:
        o o
        o x x o o
        x o

        ‘x’ means that the corresponding AF sensor does not find any focus position, while
        ‘o’ indicates that a (proper) focus position is found, at least if there is enough contrast.
        My 650D, however, finds the focus also at much lower image contrast, where none of the 6D sensors succeeds. For me, this looks more like an electrical rather than an optical issue.
        What do you think?

      • Thomas Loebl says:

        Hm, it´s really a little confusing. The AF sensor is one package with lenses at the front… nothing to dismantle. May be that the flex has a cut, may be the connector or the next board. If there are a few normal responding and others 100% not, then i would have a look to the flex cable with a spyglass. The problem for replacing is the adjustment afterwards. I don´t know if there is a possibility to solder only a new flex without moving the AF sensor. All other things are too expensive (to change the shutterbox…) and need calibration too.
        here´s an explaination and an example for this sensor.

      • canonrepair says:

        Don’t forget one more thing: the AF sensor can work accurately ONLY if the light beam coming from the outer diameters of the lens can rich the sensor without any supplementary reflections or diffraction – and the whole optical system must be CLEAN. The case you have a dirty secondary mirror, or the main mirror is dirty on the front or back side, the AF will NOT work correctly.
        So, check the mirrors, and the AF lens.

      • Erwin Lotter says:

        It was the optics! The back mirror in the AF-unit is broken, but partly still in place.
        I’ll try to replace now.

      • canonrepair says:

        well, i am happy to hear this. 🙂
        and to find an another mirror is not so difficult.

      • Erwin Lotter says:

        Done. Luckily the new mirror seems to sit exactly in the same place as before, because all AF fields find the right focus position now. Many thanks for all hints and advice!

        Btw.: I think that this kind of defect should be very uncommon. When cutting the replacement mirror I found that breaking such a piece of glass (20x10x1 mm) is so hard, that this shouldn’t happen by accident without damaging much more parts of the camera. I believe that this mirror was already broken when the camera was assembled. Dropping the body now probably disarranged some of the mirror fragments out of their normal position.

      • Thomas Loebl says:

        Hello Erwin, a break of a sub mirror is not a common problem… only caused by an “accident”. But there are several souces where you can buy such a part. I have never “cut” such a mirror, cause the thickness and the correct beam path is important of the AF-result.
        For example…
        All the best, Tom

      • Erwin Lotter says:

        Hi Thomas,
        an interesting link, thanks. The mirror which I replaced was not a moving one. I think I wouldn’t be able to accomplish such a job without original spare part. There is another mirror inside the AF unit, between lens and sensor. This mirror is accessible from the outside (from the bottom of the camera) without removal of the AF unit.

      • Thomas Loebl says:

        Hello Erwin, i´m a little confused with your reply… The AF unit is a fixed but adjustable part in the bottom of the shutter box. But it has no own mirrors- only lenses. Inside the shutterbox you have two moving mirrors; the big one is for viewing, metering and the light meter. The sub mirror behind is only for AF. It is a 100% mirror, but has to be aligned.
        Look at the “yellow box”- this is your AF sensor. And you can see the sub mirror above. So you can imagine what a false diameter or angle will cause.
        Regards Tom

      • Erwin Lotter says:

        Hello Tom,
        there are different designs of AF units in different camera models. Some have a linear light path, like in the 1100D, while others include a mirror which deflects the light by 90 degrees. The reason, I guess, is to reduce the length of the unit. I have seen this design in the 6D now and earlier in the 600D.

  43. Todayshorse says:

    Canon 30D question.

    Hi there, my Canon 30D shoots 5 shots then error 99. This repeats after switching off and taking the battery out. Does it with lense and cf card or without. New CR2016 battery fitted. The mirror appears to work as does the shutter although somthing is protruding from the top right of the shutter. It does take images and shows them on the LCD and they save to the CF card. Shutter button is a little laggy.

    Is there any hope? Am willing to take apart as it only cost me very little.

    Many thanks!

    • canonrepair says:

      I think the problem is with the shutter. there are 2 mechanical contacts in the inside, which probably are worn/broken. You can replace them from an another shutter – but at first you will have to take out the shutter.

      • Todayshorse says:

        Ok thanks for your reply. I have since pushed in this protruding ‘thing’ which seemed to retract all by itself.

        Now I can shoot all day long with no error 99.

        Annoyingly anything shot without flash appears almost black, inside with flash, the images are perfect.

        On bulb setting the shutter opens and nothing is in the way of the sensor.

        Really thought I’d sorted it with no more error 99 but I guess not!

    • canonrepair says:

      when there are ALWAYS 5 shots, that is more interesting. (working like a counter)
      I have seen this by a 350d – no solution, excepting battery out/in. was probably a mainboard fault

    • Tom says:

      This can be the shutter itself or the motor. The 30d should not have a cleaning function. The sensor is aligned by spacers only and does not rest on springs. So i will be “easy” to change this part. The older series have problems with the magnets of the motors. There could be the problem too. So it would be helpful to have a look at both- the shutter and the mirror box.

  44. Toni Hallikas says:

    Canon EOS 1Dm2 (N)
    Takes one photo and immediately displays ERR99. Power off and power on and same thing happens. Mirror- or shutter mechanism contacts?
    Took the body apart and shutter is open.. should be closed.

    • Tom says:

      Hi, the older 1D series has an external loading system and a “passive” shutter- means closed by two magnets. I have had this error with a damaged loading system CG2-1242 (only a mechanical issue) and a problem with the curtain blades of CG2-1162. Numbers here from a 1DSM2. Advance: you can fix it without attaching the sensor from the mirrorbox side.

      • Toni Hallikas says:

        Thank you. Well, I do have two shutter charge units for 1Dmk2 so I could try another one if you think that solves the problem. I took the shutter unit off and it seemed to be ok, both blades are loading and releasing as they should. Not sure about the contacts.. I forgot to measure them. What did you mean about without attaching sensor? Would be pleasure to find out some easier way to fix this, because its a big task removing the whole mirror box assembly from 1D series.

        Regards, Toni

      • Tom says:

        Hello Toni, the only way to pull out the shutter is from the shutterbox side. But it´s quite easy and you don´t have to align the sensor (like in a 5D). Loading unit- try out if the loading arm (which loads the shutter) snaps back. In some cases it will be torn and stops the process. If it is ok and you´re shure the one curtain will function and the other not: check the two coils and a freely closing of both curtains. The last- we don´t hope- would be the drive for the coils of the pcb. But if you dismantle the cam, you can see the loading process and check the coils and the voltage.
        Regards Tom

      • Toni Hallikas says:

        Ok, weird things happened. I tried 1sec exposure, shutter did not open and err99 appeared after exposure. Tried sensor cleaning, shutter did open as it should but as soon as powered off and on, shutter mechanism engaged and err99 appeared. Power off and on again and it took a picture – no err99. Tried burst shooting at full speed, still no problems.

  45. Jiří Dejmek says:

    Hello, thanks for making your work public! It is the best way to understand DSLR work and can how can it be DIYed. 🙂
    I bought 6D last year, but after few months of using It wont recongnize some SD cards that used to work perfectly well in that camera (mainly micro-SD-to SD adaptors). After inspecting SD slot from outside the camera i Cannot see any leftover plastic pieces of deffective cards or bent pins (looks exactly like my 60D SD slot though).
    I have two SD cards working almost every time and some not working at all, although in my other cameras and readers they all are perfectly working.
    Tried to clean SD contacts with IPA and contact cleaner with APS-C cmos cleaning swab but it looks like no luck so far… Im desperately trying to avoid changing SD slot mechanics because it apparently means soldering. 😦
    Do you have any other suggestions? My next step is bending card reading pins litlebit more but not sure if it is good idea.

    • canonrepair says:

      Look, in normal conditions bending the pins from the slot helps – but NOT from the outside of the camera. You will have to have access from behind of the slot too, so at first, you have to take out the mainboard, with all the risk what that means…

      • Jiří Dejmek says:

        It worked like a charm… First of all I did not touched any of card pins just the pin that check card presence on this picture ( it is not accessible from motherboard any better than from outside the camera…
        I bent smaller pin towards the bigger one just a little bit by tiny 0,4mm thick metal hook from my chinese endoscope camera set and voila! Now it reads any SD card again!
        Offcourse I’ve did it with removed battery and with maximum care to not touch any other pins inside.

      • canonrepair says:

        I see. This is something else, you are right, it must be done from the outside.
        In worst cases i just take out this contacts, and the camera works without them.(just with a bridge on the board,)

  46. Dolf Gregoire says:

    I also have a Canon EOS 1000D and after years without problems, I now have the buSY error message. No display (LCD monitor) ) and the computer doesn’t recognize the camera (USB).

    The camera was doing fine and I have/had no reason to replace it.

    Does anyone know if it makes sense to replace the second battery in the camera. I saw this in the Dutch manual (page 189). You are advised to remove this second battery before you discard the camera. This second battery is not listed in the English manual.

  47. Iconbetta Iconbetta says:

    Canon 7d MarkII DC board problem.
    I love this blog, so many times I found it helpful and pointing in right direction how to repair my stuff. It started to me as fixing the photography equipment because I couldn’t afford it.
    I am going back to repairs I have had some break of it for some time
    I did fix a DC board in numerous canon 5d mark II but I can’t locate any fuses on 7dmkII one.
    Did you have one in your hand? Would you be able to point me where I need to looks for them fuses?
    Thanks in advance

  48. Alberto Dos Natta says:

    Hello again!

    I’ve asked for your help recently and your suggestions we’re the most accurate I’ve found online about Canon reflex diagnostic and fixes.
    So, I would ask for your valuable opinion again. I’m trying to repair another Canon 5d Mark II for a friend of mine. Well, it has exactly this kind of problem: The reflex is always on, the only way to shut it down is by opening the battery door, plus the LCD screen is lit, but no image appears. I’ve already tried to swap the rear panel with the on/off switch from a donor reflex, but to no avail for both the problems, suggesting me there is a open power pathway somewhere. Any suggestion?

    Thank you in advance for your excellent job

  49. Lucas says:

    I’m run it to the problem with my Canon 7D. One day when i try to start camera empty battery icon flashes. I did read that bottom screw tempt to fall out. Have check that but no issue at all. Then i decide to probe DC-DC board and find out that one chip MAX8682 is shorted to ground. So I replace that and seams camera start to working fine. But it not so fast. All function work as they should. You can make a picture, record to card and operate menu. Up to you switch on live view.
    Camera freeze and err80 coming up on top LCD after 10-20 second. Back LCD is blank. Before err show up can not operate beck buttons. Only top ones working correctly except shutter release button. So now I’m stuck with partially working camera. Err80 Is related to image problem so decide to disconnect CMOS from motherboard. This trick seems to work as when its disconnected camera working fine even in live view mode except there is no picture for obvious reason.
    That`s mean CMOS sensor is faulty or other part??

    • canonrepair says:

      I think, you are right: “CMOS sensor is faulty or other part”.
      This menas, that without a second, known working camera used as a testbench, will be hard to find the real fault.

    • Tom says:

      Hi, a common mixed up Problem… with the screw it means mostly a ERR40 and a dead Flash/Driver board; blinking battery means dc/dc. But i´ve seen some Bodys with a Problem in both boards. So check both. Your other Problem: check all Connections and Flex cables. If there is all ok – check the shutter box. There is a Problem with the Motors. If everything really is ok, Then i would think about a dead Mobo. If you can make a Picture in view finder mode, i don´t think your sensor´s faulty.

  50. Gerardo Pane says:

    Hi again
    Just to recap, my Canon 5d Mark II stoppes working after being in my backpack in a rainstorm. No water on the camera but probable from the dampness crushed by the wet backpack
    When the power switch was turner on. The back LCD didn’t turn on. There was no usual red (read/write) light on the back of the camera but the top LCD went on with parts of the symbols missing, all the focus points lit up in the viewfinder and i could move them around, Aperture could not be changed and there was no info in the viewfinder but oddly enough with a little turning of the top dial eventually i could change it and the bottom display info in the viewfinder would turn on.
    Well, i took advice from here and placed the camera( took all batteries out and opened all compartments) in a plastic box with a container of Damp Rid( calcium chloride) and let it sit in there for over 2 weeks.
    I dismantled the camera and took out the top dcdc board, main board and bottom board. I cleaned everything on the camera with a qtip and rubbing alcohol and same with the boards. I also sprayed the boards with 0 residue electrical contact cleaner and reassembled the camera
    But it didn’t help. I have the same results except that now only the right side of the focus points light up in the viewfinder and I still see no life from the red light on the back of the camera, the top lcd still goes on but with parts of the numbers and symbols missing( but if I tilt the camera a little I can see them ) and the aperture can’t be changed and bottom info in viewfinder doesn’t come on unless I fiddle with the main dial and turn it to different modes eventually I can adjust aperture and the info on the bottom of the viewfinder turns on
    Sorry for the long post and if I repeat mysel but I am wondering which board should I change if this is a board issue or is this camera just done and I should forget about trying

    Kind regards

    • canonrepair says:

      “i took advice from here and placed the camera( took all batteries out and opened all compartments) in a plastic box with a container of Damp Rid( calcium chloride) and let it sit in there for over 2 weeks.”

      I think nobody adviced You this. washing with destilled water and blowing out. Not a desumifier salt.
      Anyway, the problem is probably on the main board. Under the main chip there are approx 300 pcs of contact balls…. and there are many chips.

  51. Gerardo Pane says:

    Canon 5d Mark II problem
    I was hiking and it started to rain really hard. I put the camera in my backpack and headed back to camp. When I got back the backpack was really wet but the camera wasn’t wet but when I turned it on the back LCD does not work and the shutter does not fire. The top lcd goes on but it displays only parts of the the numbers(iso, aperture, shutter speed). If I turn the top dial, I can see the numbers changing and also if I push any top buttons or turn the main dial I see the changes on the top lcd.
    Any ideas on what can be damaged and what I can do to try and fix it myself?

    • canonrepair says:

      COMPLTETE isassembly AS SOON S POSSIBLE, and drying with pressurizedair, pure alcohol etc.
      bring it to a workshop if you have no experiaóence in that.
      the problem is not only the rain – but the salt which is now in the inside, coming from the former transpiration for ex.

      • Gerardo Pane says:

        Ok. Thanks. I will give it a shot.
        Right now, i have it in a plastic box , sealed with a container of DampRid(calcium chloride). Figured i will leave it for a few days in there than try disassembly & cleaning

      • Tom says:

        If it got wet only with fresh water… Then it´s ok with drying it out. But if there is any salt you have to swipe it out. Salt will “eat” all parts on the main board, causes corrosion and Shorts. Some flood the parts with deionisized water and after that use isopropanol to clear the rest. Please be careful! In some cases a not completely cleaned board will first work for a while… and Then it Fails.

    • Gerardo Pane says:

      Hi Tom. Thanks for your reply
      I am in Norway and was hiking on a mountain. So it was rain water What is strange is that once the downpour of rain came, i put the camera right into my back pack. The backpack was totally drenched and it was damp inside the pack when i opened it but not wet. So the camera never got water directly on it
      I’m guessing it condensation that built up in the backpack. Little upset that a 5d Mark II can be so sensitive. My 80d has been out it the rain and in the same backpack with no problems ever.
      Hoping I can bring my 5d back to life

      • Tom says:

        Hi, only the 1D series are better protected against dust and raindrops. None of them is nearly “watertight”. The problem can be humidity caused by the rain or from the temperature drop. I hope you have luck. But pls have a look at all metal covers inside. They may rust and make shorts. Regards Tom

      • Gerardo Pane says:

        I will attempt disassembly tomorrow.
        AS of now, after the camera has been in a sealed box with damp rid. The lcd goes on(still with missing segment) and there is life in the viewfinder but get No CF card error when i push the shutter button. And back lcd still doesn’t go on. Can’t find my CF card so will have to check it once i find it:)
        What i also noticed is the red light next to the back dial does not light up when i insert the battery like it used to do and if i connect the camera to my PC it is not picked up by EOS utility
        Is there anything specific I should look for once i open it up as to why the red light doesn’t go on. Is there a certain board that controls that?

  52. m.udaykumar says:

    cannon 1200d camera geeting error 30 comming why its coming how to slove that problem

    • canonrepair says:

      Err 30
      Description: A malfunction with the shutter has been detected.

      can be a lot of things: shutter or onl the blades of the curtain, main board, or the phase sensor

  53. Tom says:

    Hi, i try to figure out why a USM gets defective. Normally it gets slower and slower till it stops. But why? Nothing is broken, there is no electrical defect. All parts are massive and i most cases we cannot see any abrasion. Do you know where the Problem is?

    • canonrepair says:

      the USM motor (and the easiest is t understand the ring-USM) is a friction-clutch. So its out-ring is driven by the 3 rollers, which are between the manual and the automatic (ultrasonic driven) rings – and they have to have good adherence, not too much slip.
      Aftrer alot of work the surface of the rollers and the surface of the USM ring will be polished, very-very shiny, which makes a high slip. And thats the end.

      Of course, there is a help: with unpolishing the surfaces I repaired a lot of them.

      • Tom says:

        Today i have had a sigma 105 USM with a bad AF. The part itself is built like the Canon original. But there is a big difference: sigma (and tamron) uses brass metal for the usm Motor. The counterforce ring part is Aluminium too, but it has a painted Surface (black). This Surface has to be polished and painted. If you try to unpolish this part… the black painting will rubbed off- and now you have only alu! And that´s the end of the usm. It will stop at once. So, both companies have “built in” a self destroying mechanism… And you know, from both companies spares are not available 😦

      • canonrepair says:

        if possible, I avoid to repair Sigma…

  54. Erwin Lotter says:

    Hello, just hit this site on my search for Canon shutter infos. I’m trying to analyse the timing signals of a 600D’s shutter in order to replace it by an electronic emulator (an arduino) for long exposure astro imaging. To better understand the signals it would really help if I would come to know what the coils within the shutter unit are good for.

    • canonrepair says:

      Hi, the shutter has two curtains, which both are cocked by the shuttermotor with a cam mechanism (Nocken in Deutsch). The curtains open and close against their springs, so case the motor would make a complete rotation, the curtin will open and close – DRIVEN BY THE MOTOR.
      Now, the curtains can be hold in the “open” position by their small electromagnetic coils.

      1. The motor rotates till both curtains are cocked (springs are under tension), but stops right BEFORE they would run back.
      (this is the base position, even when the camera is switched off!!!)
      2. You press the exposure button, the motor gets a short signal, rotates more – but in the same moment both coiles get signal too. Motor rotates more – but the curtains are hold by the magnets. (one is open, one is closed)
      3. One coil is interrupted – that curtain will open – this is the beginning of the exposire
      4. after the exposure time is ended, the second coil is interrupted too – this is the end of the exposure. Curtains: one opened, one closed.
      5. the motor cocks the shutter again, prepares it for a new exposure.

      is it OK now?

      • canonrepair says:

        By the way: try to put on the oscillocope the signals of the cam position sensor too. will help a lot!

      • Erwin Lotter says:

        Thanks for the explanation, you pushed my understanding a lot. I think I also got an idea now why in LiveView the rotation stops a bit before “fully opened”: In this mode of operation both coils are released (probably to save the coil current) while the state still is stable. But anyway both coils are fired in the beginning of LV (for about 180 milliseconds),
        In between I succeeded with the emulation of the 600D shutter. I will add the description and software to the one for the 1100D which you can find at

  55. Alberto Dos Natta says:

    Hello János,
    First and foremost, thank you for the excellent blog you manage: it’s one of the most helpful resource for us DIY enthusiasts.
    I’m trying to troubleshoot a friend of mine Canon 5D Mark II. The camera turn on, but there’s no image on the LCD screen nor on the top display. Everything seems to work fine, the camera takes pictures, autofocus, exposure time rolls up and down when i use the wheel and so on… but there’s no image nor info. I can’t really understand what’s going on. Do you have any suggestion?

    • canonrepair says:

      Hi, the 5dII has a LOT of fuses on the DC DC boards. Try to measure them with a multimeter. Would be greata donor tho check to replace the boards.

      • Alberto Dos Natta says:

        Thank for your quick answer János. I’ve already checked all the fuses, they are all ok. I’ve also switched the rear panel with another Mark II to ensure there was no communication error between the LCD and the motherboard (which I’ve also tested). It’s a weird problem I’ve never saw before.

  56. Rolf Wollesen says:

    Hello. I am repairing a Canon 24-105mm f/4 version 1 lenses, and I have started to get a headache… The lens had the 01error, and I fixed that by changing the aperature unit. But now I have reassembled it, and I get this annoying sound at around 24mm. When the lens is pointed towards the sky (the front element) it sounds like a cable with tape on it is going lose from the plastic and sticking back together… But oddly enough when the front element is pointed downwards the sound dissapears? So it is only when there is pressure from the front element… I have tried to se if any of the cables from the USM motor is loose, but I can`t find the cable that is making the sound… Have you had this problem or do you have any idea of how to fix it?

    • canonrepair says:

      Are You sure that the focusing lens (that one which is behind the front lens) is engaged with the USM motor? It s a typical failure, that during assembly the plastic rod does not fit to the usm.
      By the way, are You SURE, that you made EXACTLY the same knickpoints on the new cable, like it was originally?

  57. situs poker terbaru says:

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  58. Hi, I just got my hands on 15-85 Canon lens damaged by water, for me it is quite interesting lens so Id like to repair it and use it for myself. Authorised service center told me there is faulty USM motor and stabilizer (because AF and IS is not working, they said absolutely nothing about mainboard but repair cost they told me was ridiculous :(.
    During my inspection I’ve realized that there was just a few drops inside on the mainboard and whistling sound is made by faulty inductor on it… it keeps whiste even when no electronics is connected to mainboard. Do you know whats purpose of induction coils on lens boards? Is it possible that faulty inductor can cause lens electronics to not work inspite of aperture control is still working just fine?

    Thank you for your blog, It is really inspiring and encouraging me to try to figure all my canon issues and keeping my photo equipment costs down.

    • canonrepair says:

      hi, that inductors should be parts of switching supplies. could be that you have some hidden shorted pins, that makes the dc-dc converter to work on full power, thats why has the sound

      • Jiří Dejmek says:

        Thanks, after some tinkering around and ultrasonic cleaning I finaly gave up and sold it as a manual lens to other enthusiast.

  59. Mike says:

    Hi! Do you by any chance know what type of connector Canon uses for motherboard to top cover connection on Rebels? You know, white with red and black leads? I’ve spent an hour looking at molexes and JST’s and none seem to match. Thanks!

  60. Laca says:

    (az imént írtam Facebook-ra, de látva a dátumokat, inkább itt próbálkozom : ) )
    Van egy sokéves (talán 5?!) Canon 1100D-nk illetve egy hozzá tartozó (ezzel vásároltuk) EF-S 18-55mm IS II objektívünk. Ez utóbbival lett sajnos problémánk. Jelen pillanatban a fényképezőgép használhatatlan. Az auto fókusz úgytűnik halott. Nagyonhalk kattanást, illetve, hogy is fogalmazzam meg helyesen…tizedmásodpercnyi erölködéses hangot hallok az objektívből, mintha megszorult volna, vagy nem tudom. Persze manual fókuszra állítva oda-vissza tekerhető, mindenféle erölködés nélkül… Találkoztál már hasonlóval? Kuka a cucc? A közeljövőben kell a fényképezőgép, ha ez meghalt, be kell szereznem egy másikat, sajnos a budget csak használtat (lutri) enged meg számunkra.
    Előre is köszönöm a válaszodat.

  61. Dana says:

    On my LCD screen, there appears a horizontal line half way down the screen. Its not on the glass, but rather on each image. the camera is a 5d mark ii Thanks

    • canonrepair says:

      you have to take off the back panel, to check the cables. can be the cable, the lcdetc. The easiest would be to check with a donor where are you from?

    • MIKE says:

      Hello, i have a Canon 70d with broke shutter curtain, i have replace the curtain and everyting is ok, the problem is that i forgot to measure the initial position of the processor, can you tell me please what is the values to put back as the initial position. PS i have read your post with the recalibration, and i own the equipments necesary to do that.

      Thank you in advance!

  62. Toni says:

    Canon 7d is not focusing without Liveview. I assume I located the fault, a bad ribbon connector on main board.. the one going to AF unit. Please read more from thread I started on and take a look at the picture on page 2.
    My questions are: Any suggestions repairing that?
    Tried to clean with no luck.. I might try to replace it but it’s so damn small and it seems to have a multi layer board, so is it solderiable at all?
    Soldering the cable straight to the board or any other good suggestion?
    Also if you happen to have a pinout to that.. What are those pins on the left? Any of the sensor outputs that could have break the sensor as well in case of short? It was quite corrored when I opened it for the first time.

    Thank you!

    • canonrepair says:

      Sorry, but case you really want to get an answer, dont send here only a link, on which I have to register at first to see a photo. Make a short description, insert only the needed photos.

      • Toni says:

        Sorry I didn’t know abot log in.

        Here’s the problem:
        Canon 7d autofocus doesn’t work when used through viewfinder, seems like connection to the lens is somehow disturbed when I move lens AF/MF switch to AF postition. It won’t even try to focus (nothing moves) from shutter or AF-ON button, also an aperture blades won’t move when depht of field preview button is pressed. I can see and change aperture numbers on display so I think it still sees that lens is connected.

        When I flip switch on lens back to MF, I can focus manually (no conf.) and can take a picture. Also aparture blades will move from preview button.

        Everything works good when using Liveview.

        Seems that I found the problem.. At least few pins at one ribbon cable connector are corroded quite bad and cable itself leads to AF sensor.
        Now I just need to get it fixed somehow. If I knew those pins are input or power to AF unit I’d assume I have to clean it better or try to replace the connector. Or is there a fuse somewhere?
        If they were outputs from AF unit, could the unit be damaged ?
        How do I upload the image? Here is another link to images:

        Thank you!

      • canonrepair says:

        i think to change a damaged socket on a mainboard is muchtoo difficult (at first, you would have to desolder one from an another mainboard, and then soldere it on its new place – I am not sure, that will survive. better to clean the contacts and reosolder the pins of the socket in place. You will haveto preheat the whole board before, as the PCB will take away the heat from the soldering iron.

    • Tipiapa says:

      Hello Toni. I’m experiencing exactly the same symptoms in my 7D. Haven’t opened the body yet. Were you successful in cleaning the connector and putting it back to work? What do you think was the source of corrosion? Extrrnal water or some kind of dielectric coming out of a capacitor?

  63. Thiago Ferri says:

    Hello sir,
    I bought a Canon 5D Classic (Mk I) last week.
    In the first 2 days, everything was fine.
    Suddenly, the camera started to turn off, and turn on again randomly.
    Now, the camera won’t turn on… When I take out the battery and put it inside again, the red flash lights very fast, but nothing happens. Sometimes the shutter clicks 3 times.
    I have checked all the micro switchs, and all the fuses from the energy board and from the DC/DC board, evertything was ok.

    Any ideas are much appreciated, thank you!!!

  64. wachenanggo says:

    i would like to ask how can i make sure that the motherboard of my canon 70d is bad?? i feel about at the center(it is on the preview butonsss what i mean) is heating aa little bit when i try to turn it on. is it the mother board is bad?? or could i just replace a ic in there.

    • canonrepair says:

      I am afraid, that nobody can tell you this for sure. case you have failure sympthoms, the easiest is to replace the board temporary, and case the failure is away, that was the problem.

      • wachenanggo says:

        there is no err code or many responds in micro switches. can i transfer another motherboard from a working canon 70d?? can this damage the working motherboard by swapping them??

      • canonrepair says:

        you can take an another motherboard – but you will have WRONG calibration data, because they belong to the other camera. You will need service sorftware for this.
        It will work, I am sure that nothing will happen – but the repaired camera will never work correctly. You can then adjust MECHANICALLY the autofocus through the CMOS positioning (see in my blog), but that is not a correct way, just a help in a free workshop.

      • wachenanggo says:

        thank you for your response sir i really appreciate it. ill just buy a new camera because a spt software + the motherboard is too expensive from buying a new one. thank you!!! 🙂

    • Filip Lolic says:

      From my personal experience, and from the talk I had with official service center here in Croatia, if 70D does not want to power on it is always problem with the motherboard. Only solution is to replace it.

      • canonrepair says:

        sorry, but this CAN BE true – but is NOT ALWAYS true. A simple contact problem can have the same sympthoms (a microswitch, or a cable, or a soldering or a ….). Do you think, that in the official service, if after replacing the board if the camera is still dead, and the will find the real problem – will theyput back the old motherboard and tell the customer that it was only a contact problem?! It is not realistic, as they know, that motherboards are USUALLY bad – so why not to replace for the highest security? (and for the customers money….) .
        So, in the statistic, the problem will be ALWAYS the motherboard 🙂

      • Filip Lolic says:

        János, I agree with you completely about dead camera problem, BUT…
        Last week I received two more 70D cameras, one with intermittent shutting down/restarting problem, and other that is completely dead. First one was easy to fix, corroded power switch brush because of water ingress.
        The other one has typical symptoms of dead motherboard. And yes, the motherboard is dead just like on the other few 70D cameras that I repaired during the last year or so. I checked every connector under the microscope, replaced DC/DC board, assembled/disassembled camera numerous times without any change, camera would still be dead. I tried to install another motherboard from the working camera and guess what? Camera worked. So, problem is definitely dead motherboard.
        Symptoms are camera does not want to power up, when you insert battery and turn power switch to ON, you can see hint of a segments on the top display, if you look at it at shallow angle.

        About the possible repair. The standard solution is to replace motherboard, but those are quite expensive plus need to be reprogrammed. I have spent many hours trying to diagnose whats wrong with the board, is it hardware or software problem. I have dumped content from both w25q64 and M95256 SPI flash chips from different cameras, but I think those chips contain only camera specific calibration data. Comparing dump files you can see they are different, but not in a “wrong” way (no data corruption). Unfortunately I don’t have programmer that can read main NOR flash chip where the firmware is…

        After I exhausted all software options, I decided to try to reflow Digic5+ chip. Fortunately I have IR rework station that can do that job quite easily, and guess what? After reinstalling motherboard camera get back to life!

        So, my conclusion is that culprit is bad Digic5+ chip (bad chip by itself or bad soldering process in factory or cracked solder joints after some time). This camera gets really hot during video recording, I am quite confident that to be a reason for failure.
        If the problem is not solder balls under the chip but the chip itself, new (?) ones can be bought from China for 50$. But you need to have quite advanced rework equipment to replace those…

  65. Bjørn Inge Knævelsrud says:

    Canon 5d ii black LCD problem:
    After I dropped my 5d ii into a small puddle (freshwater) the rear LCD is completely black. There is also an overnight battery drain. Everything else is working perfect.
    I have replaced the LCD with a new eBay replacement without any effect.
    I have also measured all the fuses in the power distribution board and bottom PCB, they are all intact.

    Any ideas are much appreciated!

    • canonrepair says:

      Hi, unfortunatelly can be that you have some water under any of the cables or sockets – or even some IC-s.
      Case a camera falls into water, you have to disassemble intirely, and to blow out with STRONG (clean!) compressed air, and sometimes to rinse wih pure water (distilled) then alcohol, then air again.
      Check the board with the socket under a microscope.
      Good luck!
      Case you cant fix the problem, you can send it to me (in that case I will send you a previous price offer of course)

    • canonrepair says:

      by the way: try to put back the cable a little bit movd again. could be a simple cable position error too.

  66. Filip Lolic says:

    This is not a question but an advice.
    After a long search for adequate screw locking glue that goes on the outside (not between the threads) I have finally found it! 🙂
    It is product from Chinese company Kafuter, type K-200R (red) or K-201G (green). Those are available on Aliexpress and eBay for around 10USD for a 75g package.
    Curing time is few minutes (dry to the touch), it fully sets in an 30 minutes or so. When dry, it is not hard and brittle and remains somewhat flexible. Comparing it to the stuff that Canon uses for locking screw heads and mechanical parts, mechanical properties are the same 😉


    • Frederic Schoovaerts says:

      Dear Filip, I think you’ve found THE acceptable solution. After many hours of research facing a similar problem (static picture= white or colored with horizontal stripes, ERR 80) I came to the conclusion that I should be a problem of digic5+ and reflow/reballing. I ended up searching for “reflow 70d static picture” and found today this very nice website. I ordered already last week a cheap reflow station from amazon (858D). I will do the repair soon. I was about to heat up the digic5+ at about 217° for a few seconds, slowly going to that temperature to avoid thermic shock. Can you please advice with the best way (temp etc.) to do it or at least how you’ve managed to do it. Anyway thank you so much! Your post confirm the final diagnostic. Long life to this website !

      • Filip Lolic says:

        Hi Frederic,
        Can you please share that website, I can’t find it?
        About the reflow soldering fix, remember that my experience is based on only one camera, but I am quite confident that next one I eventually receive would be possible to fix the same way 😉
        I am doing BGA rework on a daily basis. Beside digital camera repair, I fix laptop motherboards, game consoles and mobile phones on a component level. So I have years of experience with that kind of stuff.
        I will try to describe how I did it, and how really whole process should be done.
        First, remove all that you can from PCB (backup battery, plastic cover from flash optical feedback sensor, two cables that go to DC/DC board). Put the PCB in the (reflow) oven and bake it at 110C for a few hours. That will significantly reduce the risk of PCB delamination due to trapped moisture in FR4 laminate. I am using regular small kitchen convection oven. After that I put PCB on my DIY IR rework machine. My machine has both bottom and top IR heaters, but for a small BGA package as Digic processor is, I am using just bottom heater to preheat PCB, and for actual reflowing I am using my Aoyue 852A++ hot air station. But before reflowing, you MUST put some no clean flux under the Digic processor. I am using liquid one, I think from Kester. You can also use “tacky” flux made for BGA soldering, but that can be difficult to put under the chip (it is paste on room temperature, but it will become liquid when heated). Problem with this is that you don’t want too much of that stuff under the chip because it can create problems with solder balls dislocation.
        So, after all that preparation goes the actual reflow process. But before that you must put the adhesive aluminium tape around the Digic chip. That is to protect surrounding components and plastic FFC connectors from hot air.
        Turn ON the bottom heater and adjust the temperature to 150C. Bottom heater is controlled by temperature controller that sense the PCB temperature via the thermocouple that you put on the PCB. When PCB reaches set temperature, you turn on hot air station with the air temperature set to 390C. Slowly circle over the BGA package and watch for solder balls under the package to become melted. You can check that solder is melted by GENTLY pushing the side of the package with screwdriver, it will float when all balls are melted. But you must be extra careful doing this, any excessive movement will disturb solder balls and that is game over (unless you remove the chip and reball it). I usually check top of the PCB temperature with my top IR heater sensor thermocouple. You can also use IR thermometer, but be careful because those things can show measuring error of 10C or more.
        Lead free solder melts at around 217C, but you must reach temperature up to 240-245C. It is important to keep solder liquid (above 217C) for 45 to 60 seconds. After that you cut the heat and let the PCB to cool down. And that’s it 🙂

        Of course, you can skip few steps described above and attack poor Digic directly with hot air, without any preparation or preheater. But risk that you will kill the board rises exponentially. Remember, you MUST use the flux!

        I hope that helped a little 🙂

        One old video of my DIY rework machine soldering some laptop graphics processor:

      • Frederic Schoovaerts says:

        Dear Filip,

        Sorry for this late reply. I was overworked this week. I must say that I’ve been pleased by your very detailed response to my simple query. I’m always so pleased to see altruist people sharing their knowledges so openly, taking their own free time to fully explain and educate others. So thank you for your time and energy, for your sharing.

        1. What I’ve called the website was just this blog and my keywords on google were “reflow 70d digic5+” and no “reflow 70D static picture” (sorry my mistakes and poor english). What makes me search for theses were at first theses videos:

        2. The 858D arrived. Your teaching made me think about a solution for my lack of “bottom heater”. I first tought about an old waffel cooker but I checked the temperature that went far above 180-200°c. I start thinking of the build of an eventual thermostat but found a simple non steaming iron more appropriate. I checked the temperature with a laser probe, cotton seems to be perfect for 150° 🙂

        So I planned to “cook” for 2 hours in the oven, then put on alu foil protections and dispose on the iron. Do you think that the circuit can directly touch the metal or must I use some kind of spacer (like small silicon feet?)

        I’m about to open the camera soon but I still had to adapt my solution to your nice and complete explanations. Do you confirm 390° for the hot air?

        I now I have only one chance. I got some flux but not liquid one.

        I will be ready soon for the big jump.

        I will try to document the process and make a video if it works. I know also that it could work but only for a short period of time if the chip is in a way affected. Thank you again for everything !


        > >

  67. Yves-Eric Corbisier says:

    Hello Ruzsa János,

    I just bought a Canon 5D mkII with an error 30, so I changed the shutter. The operation went well and after reassembly the device appeared to work properly.
    After a few hours, the cleaning of the sensor no longer worked but hey it’s not too serious.
    But I can not make a clear picture. With autofocus and manual, the focus is about 70 cm too far (object placed 2 meters). The only way to have a sharp picture is in manual with the liveview.
    I wish I could fix this problem myself, do you have an idea to be able to solve that?

    A big thank you, good day.

    Yves-Eric Corbisier.

    • canonrepair says:


      I am 100% sure, that you disassembled the cmos without measuring it’s position before.
      For this you nedd a measuring stand (bench) and a dial gauge.
      the cmos is mounted on 3 elastic rubber bumpers, which are adjusted with the 3 torx head screws….

      so now, I am sure, you dont have correct focus, and the right/left, upper/lower side is also not equal.

      to adjust it back to the perfect position, has to be disassembled/assembled 2-3 times, and to be measured with a measuring bench with a precicion of approx 0.01 mm.
      case you dont have the stand, you will not be able to do it.

      • Yves-Eric Corbisier says:

        Hello Janos,
        You’re right I should have read your blog better. Going up the sensor I aimed the screw bottom, I thought there were cleats. I repositioned the sensor by measuring the height for what is the same as the three fixing and I turned the screws of the same number of turns to get the right focus (3 disassembly-reassembly). Now the photos are sharp.
        A big thank you for your reply and your blog. Now I attack the repair of a lens 24-70 f1 / 2.8, problem of opening of the diaphragm.
        Good continuation.

  68. Ivan says:

    Finally, I think I have found the damage that my camera has 60d … I found some corrupt pins in a connector that joins the sd card plate with the motherboard … This would correspond with the symptoms that the icon of the battery are blinking in the top lcd ?



    How could I lift the varnish from the flex cable to try to solder two cables to make a bridge? On the plate it is easy to weld, but I have never welded on a flex …


  69. Ivan says:

    Hi. Is there any simple way to eliminate the shutter and mirror mechanics (to remove these vibrations) in a 550d and that the camera will not show error?

  70. Bert Branje says:

    Hello János,
    do you have experience with the Canon compact macro lens 50mm 2.5. I have a lens that does not focus on infinite. With the indicator on infinite, the lens is sharp at about 20m. I only get sharp pictures from 10cm until 20m. Is there an adjustment for this?

    • canonrepair says:

      I think you just have to take out some shims from that ones under the bayonett.
      At 20 m the focal distance is about 50,125 mm. At infinite of course 50,000 mm.
      This means for me, that if you take out 0,125 mm of the shims, you will get the infinite instead the 20 m.
      Am I right?

      • Bert Branje says:

        I found the problem today. I did not mount the plastic back cover of the lens during my repair and testing period. It looked as if the cover has a glass protection, but it appears to be a lens. This is hardly visable, but after replacing the plastic cover the lens is working fine.

      • canonrepair says:

        Bert, I think , that isnot a lens, just planeparallel sheet of glass, BUT: if you have there ONLY 1,5 mm of glass, that means for the light, that has to “travel” 1,5x than it has to travel through clean air – this is a difference of 0,5 mm (!!!) regarding to clean air.
        So, this optical length difference is the solution makes for the optical system like the lens would be at 0,5 mm more distance from the cmos (the real length-difference depends on the thickness and optical parameters of the glass.

  71. Suneth Fernando says:

    I bought Canon EOS 40D from eBay, in which external flash batteries drain after few shots & batteries getting very hot. Sometimes the flash mode E-TTL to Manual changes automatically. I tried with all three flash units, the result is same-which are working fine with my Canon EOS 50D. Even I tried with new batteries for flash units result is same. Is this due to bad main PCB or hot shoe of the 40D or from both?

    • canonrepair says:

      to be onest, i can t even imagine, what happens there. the flash communicates with the body only on data lines, normally no current there.

      • cspf123Suneth Fernando says:

        Can this be happened if someone had fixed old camera flash which produce higher voyage to camera body.

      • cspf123Suneth Fernando says:

        Sort some typing mistakes.
        Can this be happened if someone had fixed old camera flash which produce reverse higher voltage to camera hot shoe?

      • canonrepair says:

        look, i can imagine that this would blow the cameras trigger circuit, but even then, a good (working) electronic flash does not put power on the hot shoe contacts, so i dont know how could this cause them described phenomena.

  72. Filip Lolic says:

    Hi János,
    Do you know where to buy those little microswitches that Canon cameras use for battery/memory card door sensing?
    Like this one:

  73. Rolf Lange Wollesen says:

    I have a question about the Canon 17-55mm f/2.8 IS USM. I bought one that needed a new IS module. I have installed the module and it is working fine. I have one problem with it, and that is the zoom that has gotten stiffer and it is not smooth all the through the zoom range. I have not really touched the zoom barrel, I have only removed the old IS module and installed the new one, by removing 3 screws and 3 plastic collars. Last time you told med too lubricate it, but I have tried that on a few 17-85mm f/4-5.6 and it is not doing anything… I am not really sure if I am doing something wrong, when screwing back in the 3 plastic collars and screws? Is there a special way of doing it? Do they have to be tight or loose? I know it might be hard too help me, but maybe you have some experience with it 🙂

    • canonrepair says:

      you probably mounted in a wrong way. what happenes when you take out the IS modul again? the moving is easier or not?

      • Rolf Lange Wollesen says:

        When I take out the IS module it is moving easier. But I know the module is placed correctly, since it has to lineup with the PCB board. But I am not sure if the plastic collars or the screws have to be installed in a special way? I just think it is a bit weird, that nobody else have that problem when they replace the aperture module in their 17-85mm and 17-55mm lenses. But I am talking about the 17-55mm, but their construction is similar. The plastic collars have a line across them on one side, but its positioning does not matter does it?

      • canonrepair says:

        If you look at the collars, at one end they have the two slots at 180 degrees, but on the other they have some inner slots, like a PH screw. Excepting the fact, that 1 slot of the 4 is a little bit tinier.
        So they are NOTsimmetrical, they are light excentric and at first you can try to put each of them directing to the same point (for ex to the front lens), but after doing the final optical check it could be, that yoou will have to adjust on their position. Its not so easy, as for this you have to dissassemble to the half the lens, to mount in a camera and to make a check in liewview, to get the best image. Affects the tilt of that lens element.

      • Rolf Lange Wollesen says:

        So do you think that the zoom has become stiffer because the light excentric collars just have been put back in randomly? Should I then have marked their position from when I dissasembled them so I would be able to put them back In the excact Way, or do their position depend on the aperature and IS module? It seems like a very time consuming process, to put Them back In one Way and then do it again, if it is not correct… Should I just start by pointing Them towards the front lens element In this case? Sorry for all the questions, but I hope you Can help me 🙂

      • canonrepair says:

        i hink the best is to point them ALL in the same direction – this is the MOST probable good position.
        normally you sould mount the lens without the zoom barrel and USM, to rich the collars. But i think normally you just have to mount it, an check the final picture quality.

  74. Jó reggelt, megkértek egy kis tanácsot Mr. “Canonrepair” -nek. Tehát vettem egy 600D-t, és az eladó azt mondta nekem, hogy nem világít, de én úgy döntöttem, hogy megvásárolom a valóban nevetséges árat. Én szétszereltem (az eladó is leszállt), és észrevettem, hogy az alaplap csatlakozója megtört és a csapok tönkrementek. Ez az egyetlen oka a kudarcnak. Az akkumulátor rendben van. Hogyan lehet megváltoztatni a csatlakozót, mivel nincs forró levegő és áramlás állomás? Mennyibe kerül, hogy megváltoztatják egy laborba? Úgy értem, olasz vagyok, és Olaszországban élök (a Google-n keresztül fordítok magyarra). Hiába kerestem információt az interneten, és végül ide jöttem, hogy megvitassam veled. Keresek információt. Nagyon köszönöm.

    • canonrepair says:

      Hi Pierpaolo,
      thanks for your hungarian mail, I was really impressed about it!
      the problem is, that to change a socket on the board is practically impossible (for me). Could you send me a photo on which I can see the damage? email:
      @ instead of %

  75. silvanu says:

    Hi there,

    I just came across your site, first of all I’d loke to thank you for sharing all this!
    I am desperately looking for a solution to my problem with Canon EOS 700D (Rebel T5i):
    When I try to focus on a big distance (MF/AF both the same, focus to infinite) like Landscapes etc. I can’t get things in focus, and things are blurry (In live view and also on the pictures taken). I have Canon 18-55mm 3.5-5.6 and Canon 50mm 1.8 lenses and they both work well with other camera bodies. So the problem seems to be the body itself.
    With the 18-55mm this problem only persists when I have a focal length of 18 to 20 mm, when I zoom in more everything gets sharp.
    With the 50mm this problem is notable from about 15 meters distance and more.

    I suppose that maybe the sensor / mirror is not placed properly or the mount ring has a faulty size.
    Maybe you can tell me your opinion on this? Up to now I’ve not met anyone who could tell me what’s wrong, not even professional photographers and photographing coaches.

    Thanks in advance!

    • canonrepair says:

      I think could be the bad lens-cmos distance. As You know when you focus on the far objects, or infinite, he lens is at the smallest distance from the cmos (film plane). When using a small focal distance (18 mm), the lens travels only a few mm from 0,5 m to infinite – and when you use a long distance (ex: 100 mm), this is travel is much more. So the lens is more sensitive for the infinite end when you use a wide lens.
      I suppose on your camera the lens can not travel to the right distance, thats why you dont have infinite – you could take out some shims beneath the bayonett. In the worst case you have to bring the camera to a workshop, to adjust the cmos distance, which needs tooling and some skills.

      • silvanu says:

        Thanks for that great description! Yes, that’s what I was also thinking.
        So I already went to one workshop and they told me to fix this they have to replace the FPC Ass’y, AF sensor and then re-adjust everything and clean the CCD sensor. This will cost over 220 Euros and I am not sure if it will really fix the problem…

      • canonrepair says:

        if you cannot reach the infinite focal point, that is NOT the electronics.

  76. Yves-Eric Corbisier says:

    Hello Ruzsa János,

    I have just come across your site and I am impressed by your knowledge and common sense, I would like to thank you for taking the time to share your experience.
    I am a handyman who likes to put his hands in the sludge (at my level) and I just buy a 5D mark II that don’t works (back screen does not turn on and the camera does not shoot) , I opened it but found nothing special but thanks to you and your site I will be able to try new things.
    Really a great THANK YOU, good continuation.


  77. Sylvain says:

    Canon EOS 400D Digital
    EFS 18-55mm
    I cannot take photos anymore because the the CF cards I tried cannot be used
    I all started after someone removed the one and only CF card I ever used in the camera: SanDisk Extreme III 4.0GB. She wanted to copy the photos onto a computer. When I put the card back into the camera it said “There is a problem with the CF card. Replace the CF card”.

    I bought a new card (8GB or more), the camera would not start up: LED ON lights up, display remains black, the camera stays like this until the battery dies or I remove the battery!
    I thought the CF card was faulty and sent the CF card back.

    I bought another one (MaxFlash 4GB 120x), same problem. I formatted the card from my PC, quick format, normal format, the problems persists.

    The CF bits look OK.

    There is a big difference between the error message when the original SanDisk card is in (“replace the CF card”) and with other cards (“the camera is like paralyzed”).

    Shall I explore with more cards, try to find someone with a 400D and ask him to test the cards?
    Or shall I have the camera repaired?

  78. Kdbcz says:

    Egy 24-105 L IS USM objektív beázás után ki lett tisztítva ill. USM motor és blende is lett cserélve. Működik minden, de csak 105-ös állásban fókuszál gyorsan, ettől lentebb lassan egyenletes lépésekkel állítja be a fókuszt. A blende cserénél az “egytengelyűség” állítást megcsináltam, persze lehet nem tökéletes. Több vázzal is ugyanúgy viselkedik. Lehet oka a nem jól beállított egytengelyűség? Vagy mi okozhat ilyet?

  79. Martin says:

    Hi there, I was given a faulty 5D MII (dead shutter.. 58k actuations). I replaced the shutter unit keeping all the screws and washers in their original places. The camera works fine now but backfocuses quite a noticable amount (can be corrected with liveview) Since the cmos using is the same I don’t quite understand why the focussing is so out. I never saw the camera work before I replaced the shutter so it could have been a pre-exisitng condition. What would be the best way to go about fixing this? Thank you for your time.

    • canonrepair says:

      I suppose, that you dont have any measuring device to check the CMOS position before disassembly and to adjust after assembly?
      There is NO OTHER way for replacing a cmos – we are talking about an adjustment of 0.01 mm tolerance.
      Case you dont have the original flange distance values, you have to determine the cmos actual position, to calculate the necessary modification of the 3 screws, to do the modification, to recheck. Normally the whole process can be done with 3 disassemblies of the main board – but you will need a measuring device and the calculator (free accessible on my homepage.
      Here is the theory:
      Where is the camera? I think, for only one camera has no sense to build a measuring bench.

      • Martin says:

        I guess you didn’t get any data as I didn’t click the send by email button, I just adjusted to the values displayed on the screen then closed the broweser.

      • canonrepair says:

        oh, I see. I just wanted to know, if the calculator was helpful or not. How many trial did you made (assembly/disassembly) to get the correct value?

    • canonrepair says:

      by the way, the pboblem is probably not only backfocus, but, as the cmos tilt is affected, you should have an non-uniform backfocus between the sides of the camera.

      • Martin says:

        Thank you for your detailed reply. I didn’t measure the original distance as the screws seem to be non adjustable in the 5D (no spring pre-load) and since I was re-using the original CMOS and mirrorbox with only replacement shutter I don’t see how the distance would have changed. I am located in Japan though so shipping is probably expensive. I have the capability and equipment here to build a similar testing rig to measure the distance of the flange-back. I thought perhaps something else could be out of align causing the focus error but if the cmos distance has changed by only removing and re-installing (how?) I can measure and try to correct with some new washers. My dial gauges (mitotoyo) are accurate to 0.01mm so I think I can get the cmos sensor to within tolerance. I will check the focus first for uniformity. My original thought was since the original shutter had failed at such low actuations It could have been subject to shock / drop damage which might have affected the alignment of somethign else besides the CMOS. Do you still think it is likely to be the cmos sensor position? If so i’ll construct some measuring aparatus this weekend. I don’t know if any software adjustments need to be made to the camera afterwards though as I have no such software. Many thanks. Martin

      • Filip Lolic says:

        Sensor in 5D mkII is mounted on a three flexible rubber standoffs. So yes, it is adjustable.

      • canonrepair says:

        Yesssss. All newer cameras have some adjustable method.

      • canonrepair says:

        beside of the stand you will need an object, can be any piece of metal, glass or stone, but perfectly parallel, which has to be approx a little bit lower than the lowest point what you want to measure. I suppose you have a gauge with 25 mm travel, so you will need this to set back the 0 point before each measuring.

      • Martin says:

        I forgot to say… even though auto-focus shows a blurred image… an image focussed with live-view is sharp all over, there doesn’t appear to be any kind of tilt to the sensor.. i shot these two images (camera level and fixed tripod, identical settings, live-view vs af)

      • Filip Lolic says:

        Martin, to check sensor tilt, you need to shoot target that cover whole field of view, you need fast lens (f1.8 or f1.4), and camera axis must be exactly perpendicular to a target.

      • Martin says:

        Thank you for your replies! I have machined the required components to attempt to calibrate the sensor. I have a 50mm travel digital dial indicator (0.001mm resolution) so I don’t need to create an offsetting block. Just two more questions if it’s not too much trouble. the first.. my cmos sensor doesn’t look like the one on your website.. there is no orientation mark on your image so I don’t know which points are which.. (I have a lower left tab, upper right and lower right looking at the back of the sensor in the camera). secondly “beside of the stand you will need an object, can be any piece of metal, glass or stone, but perfectly parallel, which has to be approx a little bit lower than the lowest point what you want to measure.” what is the purpose of this? Kind Regards

      • canonrepair says:

        “here is no orientation mark on your image so I don’t know which points are which.” in fact, has no importance. Just mark 3 point on the frame of your cmos (preferablyclose to the 3 adjusting screws. You have to give for the software the coordinates of the points, regarding to the middle point of the cmos (the whole thing seen from the back side, you take off the back panel, and you put the camera in the front of you). The program will calculate the new coordinates in the same system, as the old ones were given.
        In the text could be confusing, that the point (1) is upper laft on the cmos, but lower right on the target – but this is logical, during the lens will make a mirrored picture…
        “…an object, can be any piece of metal, glass or stone, but perfectly parallel, which has to be approx a little bit lower than the lowest point what you want to measure…” you will NOT need it, this is only the offsetting device. You have a 50 mm dial gauge, no need of this, just zero it on the flat surface of the stand.
        By the way, which gauge, for which price?
        “I have machined the required components” is this so easy to do in japan?!

      • Martin says:

        Thank you ever so much for your fast replies!. I have re-adjusted the camera and now the focus is accurate over the whole plane. The final result needs the camera to have a -1 adjustment in the microfocus adjustment to ensure the crispest sharpness but I can live with that for now as the camera was free and will only be used as a backup. I do some light machining as a hobby but i’m very lucky to have a friend who owns a local company that cuts precision gears and sprockets for many automotive applications in Japan, using his workshop after opening hours and his expertise it is easy for me to have access to high precision equipment. The finished camera holding tool was a with a bayonet from an old broken lens attached to a machined block to hold the camera, very similar to the canon design, the zero offset can be taken from the mating surface, attaching the camera and measuring the rear plane. It all worked out well anyway..

      • canonrepair says:

        happy to hear that.
        but how did you calculated the right Z-coordinates? If somebody uses my calculator on the net, I should get a feedback from the system. did you made your own one? (in fact, its not a high mathematics)

  80. Anthony says:

    Hello! I find your blog one of the most useful resources about Canon tech, and that’s the reason why I’m going to ask this (silly) question…
    I’ve got an old 5d Mark II whom I’ve replaced the shutter by myself after it went definitely down (more than 500k actuation before dying, I didn’t expected it would last so much). Before going to a Canon repair facility for the CMOS adjustment, I’ve ran into what it seems a common problem I can’t help to sort out. The fuse VD7-2292 on the upper DC board blown immediately after the reassembly. Since I had no time to work on the smd, I’ve replaced the DC board with a working one I’ve bought from a e-shop and tested before assembling… but, then again, the reflex didn’t work and the same fuse got blown. Do you have any idea where the short circuit which causes fuses to blown could be located?
    Thanks a lot for your grat work and best regards

    • canonrepair says:

      hi, unfortunatelly, i dont know which is that fuse, but case a fuse burns out, you have overcurrent, and this can be caused by a wired in short to ground, or for ex. a motor, which can not rotate normally.
      after a shutter replacement i always try to move the motor by hand (with a screwdriver), actuating the shutter/mirror. case there is a mechanical problem, the motor could blow a fuse.

      • Anthony says:

        Thanks a lot! That’s the kind of test I dind’t even think about to try… I’ll try to test mechanically the motor as soon as I’ll have disassembled again the reflex.
        I really appreciate your kindness and dedication to the DIY community.
        Thanks again!

    • Filip Lolic says:

      First, check that both motors are turning freely, use small flat head screwdriver for that.
      Second, check for a loose screw(s) that often find their way to the bottom pcb where they can make short.

      By the symptoms, it is quite possible that bottom pcb is making short, most likely problem with the dead motor driver IC (LV8013).

  81. n---s says:

    Hi there! I’m so glad to have stumbled upon your site.

    I have a 600D, the previous owner said the dc/dc board needs replacing, but I’d prefer to try fix the board myself. I can’t see any visible damage/burn marks/broken components on the PCB. None of the components feel warm when turned on.

    Where should I start? Are there schematics for this board somewhere?


    • canonrepair says:

      unfortunatelly in such cases the simples method is to use a donor. Case the DC-DC board is damaged, in most of the cases a multi-supply IC is damaged. You can tr to replace it, for that you need no wiring. And I have no wiring for it, anyway.

  82. David Milsom says:

    7D DCDC Boards

    I have a few dead 7d dcdc boards and was thinking could I repair them!
    Can anyone tell me what is the most common reason for the board to fail,
    Is there a fuse? what is the best way to test them?
    Thanks for any info/help


    • canonrepair says:

      I suppose you talk about the bottom flash and DC board. As I now main problem is the power supply IC. See this site:

      • David Milsom says:

        Thanks for the reply,
        Yes the top dc board I have had fail and have replaced with new but am looking to try to repair the faulty ones if I can.
        It may not be possible but its worth a try but not sure where to start.

      • Filip Lolic says:

        I replaced MAX8682 PWM controller on a few 5D mkII DC/DC boards, and that fixed the thing 😉
        7D uses the same controller.

      • David Milsom says:

        Hi Filip,
        How did you manage to change the MAX8682 ?
        Its hard enough soldering any surface mount components but the MAX8682 is somthing I would not like to try!
        I was thinking there must be a fuse on the board ?
        I have tested voltage on the board starting at the battery input, I have full voltage to a few components but it has 0 volts on most of the board.
        I cant find any point that is not full voltage or 0 volts …..

      • Filip Lolic says:

        Hi David,
        It’s actually very easy chip to replace, IF you have right equipment. I have used hot air rework station, some quality flux, working with precision tweezers under stereo microscope. But I must say that I have more than 20 years experience doing this stuff…
        Also I have to correct myself, the DCDC boards I have repaired before was from 5D mkIII, not from mkII cameras. I don’t know if mkII has the same PWM chip.
        Also, there are no fuses on any newer camera…

  83. Juan says:

    Hi.I’m trying to repair a 60d canon. It does not turn on. When you put a battery in it, all you see is the battery icon blinking. I thought something on the power board may be wrong. The contacts where the battery is connected are shorted. All capacitors I have measured are also in short. What could be the problem? There should be no continuity between the connectors on the battery of the power board, right?

  84. Hello, I’m repairing a Canon EOS 6D camera. I have replaced the CMOS sensor and now the image is slightly blurry. How can I go about to adjust the FFD? Thanks in advance.

  85. Rolf Lange Wollesen says:

    Hello. I am repairing two Canon 17-85mm lenses, and I have started to get a headache… I have now opened them up 10 times, and they keep giving me problems… The first problem is that when I am zooming with the lens, when it comes to 17-20mm it makes a sound, like a cable with tape on it is gone lose from the plastic. I have followed a lot of guides, and none of them have this problem. The other problem I have, is that the zoom gets were stiff… I don’t know if I just need some grease/oil for the zoom barrel? I really hope you can help me!

  86. Joao says:

    Hello, I’ve been searching for all the internet but I did not find the answer yet… I have a Canon 1000d bought on ebay 3 years ago, but last week it give’s me the “busy problem”. It says “busy” in the viewfinder, no LCD. I know Canon has relaease a firmware to correct that bug, but I’m unable to update the firmware because LCD is not working… and if I connect it to a computer through usb cable the computer does not detect. I’ve already tried to remove the secondary battery but still the same.

    Is there anything I can do besides send it to Canon?

    I have other doubt… If you change the PCB board despite of the Canon model you will have always to use STP software to initialize it? Is there other software that you can use?

    Thanks a lot

    João, Portugal

    • canonrepair says:

      I think you will have to send it o Canon, or to somebody who has SPT software. Without a service software any mainboard replacement is useless, as the calibration data, and the most important, the AF date are on the old mainboard.

      • Mike says:

        But it will still boot, right? Say, I just want to plug in a new board to see if everything else is operational and then strip the body for parts?

      • canonrepair says:

        if youreplace with an already used mainboard, will work(not correctly, but functioanally). a BRAND new mainboard could work or not, as normally needs to be initialized.

  87. Robi says:

    Kedves János,

    Egy 650D vázon dolgozom, ami elvben megázott esőben, utána egy ideig működött, majd az LCD-n megszűnt a kép. Belül csak a main nyákon látható száradás nyoma, azonban oxidáció sem ezen, sem a tápboardon, sem az LCD-n nem látható. Az biztos, hogy szoftverből érzékeli, hogy nincs kijelző, mivel a live view módot, a videó módot, valamint a képek visszanézését is letiltja (onnan tudom, hogy az SD led nem villog, miközben megpróbálok lapozni). Kifogástalan képet készít, a viewfinder kijelző működik. Ha HDMI-t bedugva kapcsolom be a gépet, kép ugyan nincs (bár utóbbi valószínűleg azért lehet, mert a monitor, amire rádugtam, elég spéci, és más eszközöknek is gondja szokott vele lenni), szoftverből visszaengedélyez mindent, megy a live view, felcsapja a tükröt videó állásban, lehet lapozni, stb. Az említett beázás után még 1-2 hónapig működött. Mikor még működött, de már a végét járta, elvben néhányszor foltosodni kezdett a kijelző, amit egy akksi ki/berakás ideiglenesen megjavított.

    Az LCD boardon 3.0V és 1.8V-os bemenő feszültséget tudok mérni, azonban semmi egyéb aktivitást nem. Szkóppal ránézve a diff párokra semmi sem látható (azaz egyik 1.8V, a másik 0V-on van). Az LCD tápkondijain sincs semmi, sehol (mármint azokon, amiket neki kellene meghajtania hogy a belső feszültségeit előállítsa).

    MagicLantern Portable display test-je bekapcsolja a backlightet (ami egyébként 10V körül van), de a kijelzőn nincs semmi.

    Soros porton a logban van néhány gyanús sor:
    [MC] PROP_LCD_OFFON_BUTTON : 2 <- ez a neten található majdnem minden logban 0, és mivel ilyen gomb nincs, nem tudom mit jelenthet.
    WARN [LVDS] First Get DTS_GetAllRandomData <- ezekből pedig sok generálódik, mintha reszetelné az LVDS linket.

    Egyébként semmilyen hibát nem ír.

    Tudna esetleg segíteni abban, hogy hogyan érdemes továbblépni? Lehet-e tudni, hogy kommunikál-e valamilyen config protokollon a kijelzővel (pl SPI)?


    • canonrepair says:

      hát az a helyzet, hogy ilyen szintre egyszeűen nem szoktam eljutni ezekkel a gépekkel. Nem mintha nem szeretném az elektronikát, de aránytalanul sok munka lenne így hibát keresni – ráadásul egy beázás általában többszörös kárt szokott okozni. Elég, ha aláfolyik egy bga chipnek, és megoldhatatlan. én biztosan eg másik váz paneljait próbálnám oda-vissza, és akkor legalább már a hibás panel biztos lenne.
      A magic lantern pedig mindenre képes – illetve képes lehet.

      • Robi says:

        Sajnos nem tudom kipróbálni másik lappal, csak hobbiból foglalkozom az egésszel. Ebayről tudnék rendelni másik nyákot, csak az a baj, hogy nem vagyok teljesen biztos benne, hogy az a baja. Önnek lenne esetleg lehetősége kipróbálni egy másik lappal (természetesen a megfelelő díjazás ellenében)? Egyébként javítottam már pár olyan laptopot/telefont (szintén hobbiból), ami beázott, és szemre mindegyik nagyságrendekkel rosszabb állapotban volt, és egyiknek sem BGA gondja volt. Ami itt furcsa, hogy annyira tiszta és ép a nyák, hogy csak fény felé a megfeleő szögben tartva látszik száradásnyom, és egyébként semmi oxidáció sehol. Sajnos semmilyen Digic IVvel szerelt kamerához nem találtam sem kapcsolási rajzot, sem block diagrammot, ami nagyban megnehezíti a debuggolást.

      • Robi says:

        Valóban BGA hibás volt. Valszeg a víztől valahol zárlat elektrolizálódhatott a ballok közé. A megoldás a következő volt: X33S-07i fluxszal jól betocsogtattam a CPU-t, a RAM-okat és a flasht. Az egészet betekertem alufóliába, majd ablakot vágtam rajta az említett alkatrészeknek. Ezután hőlégfúvóval 300 fokon melegítettem néhány percig. Miután kihűlt, izopropil alkohollal átmostam, majd sűrített levegővel kifújtam az alkoholt az ICk alól, és megvártam, hogy megszáradjon. Azóta tökéletesen működik.

      • canonrepair says:

        azért én nem merném az életemet bízni arra a javított BGA chipre….

  88. Mike says:

    Have you ever had to deal with hunting AF on 18-135 IS? The original version of it. Any idea what might be causing it? Thanks!

    • canonrepair says:

      focus hunting normally is caused by the dirty position sensor in the USM motor, I mean, dirt on the transparent optical encoder

      • Mike says:

        Yes, I know about those – I’ve cleaned a few 17-85’s. 18-135 though has an old style gear-driven focusing. I figured out by now that the problem is in the motor by swapping it out but I haven’t worked out yet what causes it to misread focus position

      • canonrepair says:

        in a normal DC motor you have on the small motors axis a wheel, which is read through an optocoupler. If that is not working, you will have focus hunting too

  89. Ryan says:

    I am working on a 60d, it will not communicate with any lens. I tried replacing the lens contacts on the camera, no change. The camera will work correctly with no lens, but if you put any lens on it you get and error 01, so it knows the lens is there to some extent, but does not see aperture or know the status of the af/mf switch. Any thoughts? I looked around for fuses on the mainboard, power board and bottom board, but i didn’t see any.

    • canonrepair says:

      i would say th top dc-dc board. you can check if the supply goes on the lens aperture, when the lens is conncted. for some reasons by this camera is very sensitive, i think is underdimensioned. replace it from a donor, but if you have some 60d customers, you can buy the dc board on stock too. will be used anyway 🙂

  90. igor says:

    it’s mean its done? those are difficult… how can I fix iy?

    • canonrepair says:

      at first, you should be sure, that this is the problem. the only method is to get an another GOOD mainboard, to build it in, and to test. Case it is ok , you have to find somebody who has an SPT software for the 70d, and to program it based on the old mainboards data, or to build the new dataset.
      Case not solving your problem, you have to replace one-by-one the others too.

  91. igor says:

    where should I look for it? which part of motherboard? somewhere around lens contacts connector? thanks

  92. Igor says:

    hi, I have problem with my 70D … sometimes (one, two times per month) when battery went flat and camera turn it self of ….I instal a fully charged battery but camera no showing f-stop number and after pressing shutter button gave me a error: comumication between lens and camera….
    basicity I cant control aperture of lens and focus on some of the lenses. what I notice : when its in error mode -and I turn camera off the SDcard LED fleshes every two second.
    interesting is: its sporadic and its gone sometimes after few reinstalling batterys and lens and sometimes after days of sadness ….
    I not using a battery grip, all batteries original, I did firmware installation when camera is normal and with error. (firm 1.1.2) . and its doing with all my canon lenses(24mm f2,8 / 50mm f1.8/ 18-135mm/10-22)

    Thank You

  93. Nagy Roland says:

    Tisztelt János!

    Először is: bocsánat, hogy két hozzászólásban küldöm el a kérdéseimet, de amikor egybe küldtem, szerintem valami baj volt vele.
    Tehát van két problémám, és a tanácsát szeretném kérni.
    1.: nemrég vettem egy Canon 17-85 objektívet, használtan. Amikor megérkezett, csak kipróbáltam egyik este, az autofókusz néhol nehézkes volt, de azt hittem, hogy csak túl sötét van a 350D vázammal használva. Most azonban kültéren használtam volna, napsütésben, és nem nagyon akart fókuszálni AF módban. Minél nagyobb a gyújtótáv, annál rosszabb a helyzet. Szóval 17mm-en kb. mindig fókuszál, felette egyre kevésbé, sőt sehogy. Másik vázon is próbáltam (600D), de ugyanez a helyzet. Hibakód nincs, nem kerreg furán, manuálisan be tudom állítani a fókuszt, de AF-ban nem megy. A blogján olvasottak alapján, mivel nincs hibakód, ezért talán nem a flex kábel lesz a ludas, esetleg az USM motor optical encoder-je koszos, hibás? Ön mit gondol? Vagy cserélnem kellene az egész USM motort?

    • canonrepair says:

      “esetleg az USM motor optical encoder-je koszos, hibás?” esetleg az
      ” Ön mit gondol? Vagy cserélnem kellene az egész USM motort?” cserélni semmiképpen. azt bármikor lehet. előbb meg kell próbálni megjavítani

      • Nagy Roland says:

        Rendben megnézem, köszönöm!

      • Nagy Roland says:

        Sikerült megtisztítani az optikal encoder-t, és megoldódott a fókuszálási problémám. Köszönöm!

        A második kérdésemet nem sikerült eddig feltennem (valamiért nem küldte el a hozzászólásomat a rendszer), most hátha. Hozzám került egy T4i váz (itthon 650D), nem kapcsol be szimptómával. Amikor megnéztem, kiderült, hogy ez nem igaz, csak az LCD kijelzőn nincs kép, a keresőben látható, hogy a váz működik. Elsütésnél a tükör felcsapódott, de kép nem készült. Az USB portja sem élt, de a HDMI kimenet igen. Gondoltam, hogy vagy alaplap hiba, vagy firmware gond, így elindítottam egy firmware update-t, azonban a legelején elment a HDMI kép. Vártam pár percet, kikapcsoltam, akksi ki, majd vissza. Azóta ennyit csinál, csak villog, bekapcsolás nélkül is, az akksi berakása után:
        Ön szerint ez mire utal? Meg lehet javítani, vagy alaplap csere szükséges?

      • canonrepair says:

        én inkább a dc-modul hibájára gondolnék. szét kell szedni, ha beázott, akkor azonnal látható

  94. huseyn aliyev says:

    hi. i live in godollo and i have a canon 60d which have a display flip problem(rotate) i want to bring it to you but before it i want to contact with you . please leave your email . thank you!

  95. Kovács Gábor says:

    Érdeklődnék, hogy javít e blendehibát?

  96. bertus11 says:

    Hello János,
    I have a problem with a Canon 60D camera, that I already had before.
    When starting up the camera I get a message that the camera cannot recognize the battery.
    I mounted the mainboard of this camera in another good working camera and here this board did not give the error message.
    So I think the problem is not related to the mainboard, but with something else.
    Do you have an idea what can couse this error message?


    • canonrepair says:

      check check data contact of the battery. is it for SURE original battery?
      60d is anyway a damned camera. I hate them.

      • bertus11 says:

        Yes I checked with 2 original batteries, same result. I already had checked the contact, but this looked ok and I also checked the screw that connects to a pcb.

      • bertus11 says:

        Finally I found the problem. There is a flex connector between the bottom board and the main board. A few of the contacts of this flex had some corrosion. I replaced the flex connector and the battery is recognised again and shows remaining power.

  97. Success! The problem with EF 300 2.8L IS (focus hunting, no encoder signal) was bad connection at aperture unit flex cable. Who would know.. now autofocus is working like a charm! 🙂

  98. Filip Lolic says:

    After few hundred lenses that passed through my hands, I remember only two cases that main PCB was broken. In both cases problem was in one of the ferrite inductors in USM driver circuitry that went open circuit.

  99. Toni Hallikas says:

    Canon EF 300mm f/2.8L IS USM AF issue

    There was AF failure, which first seemed like optical encoder failure: focus hunting back and forward two times and then stops, never locking to any subjects. I have repaired some USM lenses having identical problem and which is mostly caused by dirty or scratched plastic encoder ring. But not this time, this lens has now brand new USM unit, including encoder system. Still hunting. Could it be bad main PCB? I measured voltages from encoder (IR transmitter and receiver) and there indeed was some voltages present when pressing AF ON button. Then i used my oscilloscope to see any pulses from receiver side but there was no pulses when turning the ring. Any good ideas? -Regards, Toni

    • canonrepair says:

      are you 100% sure, that this USM is the right version for your lens?
      I know for ex that there are some micro USM motors for the 50 mm f1,4, where you have to change sometimes the board too.

      secondly: do you have the USM for a 100% official source? last time I ordered a cmos for a G9 camera from a chinese company (sold as used bur checked). NOT working. I wrote a letter – they have sent back the money immediately.

      • Toni Hallikas says:

        It should be exactly the same unit, brand new original Canon part (not ordered from China). Anyway, this new unit did not fix the hunting problem, now I’m thinking about buying new main board (costs 120euros). :/ EF 50 1.4 USM has some trimmers on PCB, which affects the usm motor (drive frequency maybe?). Once I ordered chinese replacement (new) micro-usm, but it had broken flex cable. Sometimes those usm’s are a bit tricky. I got EF 400 2.8L USM (non-IS) for very low price, 250eur. No autofocusing at all. I spent many nights while trying to figure out what’s the problem and finally noticed that it was USM stator itself. There was really tiny crack on conductive paint, backside of the stator near flex cable. I used silver conductive paint to fix it, and it did the job! It works now like a new lens.

      • canonrepair says:

        on the PCB there shoud be a potenciometer to adjust the signals frequency, but for you more important the PWM ratio – which should be 50%, and also has a potenciometer
        But this is for the driving of the USM, not for the feedback.
        Focus hunting normally means no feedback from the moving part – this case the USM gets the signal, and after a time limit will stop working.

  100. canonrepair says:

    as an intensive grease cleaner use BRAKE CLEANER, 500ml spay can is ca 5 EUR… just test it before, as there are many different types.

    • bertus11 says:

      For cleaning I use a spray from AF, called Isoclene(ISO250), Isopropanol(99,7%) cleaning fluid(250ml). I also used it for cleaning a camera sensor(outside the camera). Spray it on the sensor and blow it clean with Sprayduster SDU400D from the same mark AF. The sprayduster is perfect for all cleaning and leaves no residues. You can find it on the internet.

  101. Filip Lolic says:

    From my experience, and I have tried many different greases, so far the best one for use in modern lenses (plastic-plastic or plastic-metal contact) is Polyolefin (PAO) grease Molykote EM-30L. It is available in small packages on ebay. Smallest 1 ounce (28 grams) package is all that you need, and will last forever for use on lenses.

  102. Lukas says:

    Hello! At first, thank’s for the valuable information on camera repairs!

    I have a question about lens repair – what kind of lubricant You suggest to use on helical parts for canon USM lens?

    Background: While I am waiting for replacement flex cable for my 16-35 2.8 mk1, I thought I could lubricate the moving parts as the lens is fairly old and zooming feels “dry”. And maybe any tips for disassembling usm motor? I am replacing the flex cable that goes inside the usm motor and tells lens chip at what point focusing gear is, which means I have to disassemble USM to deepest parts and I am now wondering if the lens will need any fine adjustments after reasembly?

    • canonrepair says:

      Hi Lukas,
      for the electronic lenses I use a white PTFE-silicon grease. It’s important to be stabile in time too.
      By the diasassembling the USM: just be careful to mark the position of the flex regarding to it’s body.
      Before disassembly you have to unscrew the comb type (absolute) position sensor. and of course be careful not to damage the optical incremental sensor. cleaning with white spirit (we have in hungary a special liquid usd in medicine, or, much easyier for you: brake cleaning fluid from the automotive industry. but check at first not to damage the plastic parts.

      • Lukas says:

        Thank You! For cleaning I have isopropyl alcohol (in Latvia, where I live it is called tehnical spirit).

      • Lukas says:

        Hi! Everything went well with replacement of cable and lens is working ok now. The comb type sensor really was the biggest pain in the a** 🙂 But now I have a problem – the top metal ring with wave spring that fixes the USM is now a little loose. It moves few mm in both directions freely, but not that far to come off. Can’t understand if I need to glue it back as it was before or it is not neccesary. Anyway – what kind of glue should I use if I decide to take it apart someday?

      • canonrepair says:

        “I have a problem – the top metal ring with wave spring that fixes the USM is now a little loose. It moves few mm in both directions freely, but not that far to come off. Can’t understand if I need to glue it back as it was before or it is not neccesary. Anyway – what kind of glue should I use if I decide to take it apart someday?”
        That ring has 3 small protrusions towards the inside, which move under a collar. The ring HAS to come off by rotating to the end of that channel. And to fix you will have to rotate in the opposite direction, and to glue it for ex with nail polish in 3 points (three portions of 2 cm length.)

      • Filip Lolic says:

        May I add that with that ring you regulate pressure between USM motor components. The safest bet is to return ring to its factory position (because of that I always mark all parts before disassembling), but you can increase or reduce pressure if needed.
        I always secure that ring with Pattex Total glue, three small dots spaced 120 degrees apart. That glue remains flexible and is strong enough, but can be very easily removed if needed.

  103. bertus11 says:

    Hello János, I have a Canon 17-55mm with error-1. I replaced the flex cable and the lens is working ok now, but I have a little bit of front focus. I’m not shure if it was already present before repare, but can this be caused by the repair? Do you know how to correct this front focus?

    • canonrepair says:

      during cable replacement there is only one possibility to change the focusing: if you put back the comb-type sensor in an other position (you have there a little possiblility to play with it. This information is used for the focus correction.
      But I never had this problem, so I think that your system was so before too.

  104. Raahid Kulangarathoppe says:

    Hi I have a problem with my Canon 700 d is not working display but no problem with lcd, problem with mainboard, can I identify the display I C ? Can you show by image?

    Thank you

  105. Jonathan says:

    I recently purchased the Canon 400mm 5.6 lens refurbished from CanonUSA. The initial photos I took looked over sharpened. I was expecting at least the same performance I have been getting with my 300mmF4. Its not even close.. The photos were of a football game with the sun behind me. Nice warm late afternoon light..@ RAW 200 ISO 1250 sec F5.6 with highlight tone priority. Standard picture style – sharpness set at 7 with other values at normal setting. . At first I thought perhaps I over sharpened in camera. So I edited with my canon digital photo software bundled with my canon 6d. I manipulated the sharpness which did not clean up the images. Still looked over sharpened? After looking might be Chromatic Aberrations? At 100 percent can see subtle outlines of it? My camera body is set for chromatic aberrations/peripheral illumination correction. Wonder what could this be? Next week before I send it to the factory I’m going to do test shots using my 300mm and 400mm to ensure somehow perhaps my perceptions not distorted. But I’m about 99% sure something is not quite right with the lens.

  106. hiphopast says:

    How canon remap sensor as i Have body with one red dot and another body with white dot. I presume that they are dead/stuck pixel and they need to be remapped. I try with manual sensor cleaning and no luck. They still visible on live view and video. However on picture mode is fine. When you bump up Time to 1/5000 or faster pixels despair as well.
    So what software they use or how it is possible to fix problem.

    • canonrepair says:

      canon uses of course the service software. with the SPT software, which I use it is not possible.
      by the way: which camera?

      • hiphopast says:

        Or sorry I have two cameras both 5D MKII and both suffer for this same illness. One have white and other red. The second camera have only 6mc and shutter count at 7K but have been opened so no warranty.

  107. igor david says:

    hi again, camera is dead now! I was tried spray brake cleaner and I was blow all board with air… and after assembly together it won’t turn on!
    I think is time for new board….

  108. canonrepair says:

    fuses normally have on to a capital letter, like “K” or “M” etc. anyway, I dont think, that a 70d should have a fuse on the main board.
    try to press slightly the big BGA chips wih your finger. or you can try some cooling spray too – case is a contact problem, will temporary help. to make diagnostics

  109. igor says:

    update… I was find on opposite side of board in area where is connector for display small component with little glass on top and with two contacts (I measured it and is dead – no continuity or resistance) …. maybe display fuse? thanks

  110. Igor says:

    hi, I have a canon70D all working except back screen… even touch working because I can relate the shutter with touch but nothing shown on screen is black all the time.. I replaced all back screen but still the same problem… can be same problem like with that 500d (bag video chip) ? all problem started before month when screen sometimes just turn off by self just touch was working…. Im soo unhappy because is great camera… and I using it for video recording…. thanks

    • canonrepair says:

      hi Igor,
      there can be a lot of causes, but yes, a bad soldering could be the reason.
      The problem is, that you use this camera for video recording. During that, the cmos gets a high emperature – and so does the processor too.

  111. Vladimir says:

    Hi Janos,
    It is a great blog you set up here 🙂
    Could you give me some hint about Canon 70-300 DO?
    I bought it used with oily aperture, actually that didn’t bother me, since I’m shooting wide open, and it was cheap. The pictures are overexposed in f/8 and smaller. Also my 500D didn’t show any error. I was thinking some day to replace the aperture (I don’t believe it is meaningful to try only to clean it), but there is something that bothers me – I did some tests with exposure, and it seems that overexposure is same for a set of aperture sizes. Here are the results:
    @70mm : (4.5,5,5.6,6.3) -ok, (7.1,8,9,10) +1ev,(11,13,14) +2ev,(16,18,20,22) +3ev,(25,29,32) +4ev
    @300mm : (5.6,6.3,7.1,8,9,10) – ok, (11,13) +1ev, (14,16,18,20) +2ev,(22,25)+3ev,(29,32,36,39) +4ev.
    If I set it manually @ -1ev, the picture is OK @ f/10. It is clearly visible that for example @f/10 the aperture is more closed than @f/11. Does this happens only if EMD is faulty, or it might be a problem with PCB?
    Another question – I found parts list, and EMD is “YG2-2098-000”, is it the same as “YG2-2098-009”? I could find only the second part as spare.

    Any hints about this lens will be highly appreciated 🙂

  112. Szabolcs Mate says:

    Excellent resource, thanks!
    Fellow Hungarian here, but I’m writing in English for your global audience!
    Typical abused 50D from ebay, advertised as 9k expo. Won it for £170, but had some bad undisclosed, mostly cosmetic issues and 39k actual expo, so got a 50% refund. Good enough for that sort of money!
    Problems I had:
    1 – The focusing screen was off. Manual focusing (eye corrected) was consistently off, while AF and Live view focusing was both always spot on. Removed the shim (spacer) from above the focusing screen, and now it is almost perfect. Better than my eyes anyway in everyday use. In ideal, artificial circumstances (excellent light and contrast) one can tell it could do with a very thin spacer though to get it just right. What is the best way to make one? What would you use? Piece of paper? Plastic film? Sticky tape on the focusing screen? Also, cutting out the original odd shape, or something simpler like just the outline of the screen? Also I wonder how this could be the case, Sensor (live view and shots) and AF sensor perfectly aligned (I mean within my means of testing), but focusing screen with (i guess) original spacer out of alignment? I removed and reinserted several times to make sure it was sitting where it should be.
    2 – Usual flash mount int/ext sensor switch problem. I just removed the stuck plunger for now and use the internal flash for AF assist, and the PC socket to radio trigger external manual flashes.
    3 – I had something rattling inside, and was stupid enough to play around with it while not only the battery was in the camera, but it was turned on! (facepalm) The inevitable happened. The distinct sound and smell of electronic discharge, and one again when quickly turned over to remove the battery! Too late. Damage report: two AF illumination LEDs gone. Lucky me, nothing more serious, but still: how stupid!?! Culprit: a lose screw inside. I think it discharged the flash capacitor through AF illumination LEDs. I still don’t know today where that screw came from! Spent minutes with the camera taken apart! Any usual suspects to check?
    As for the repair, am I right thinking I can just replace the LED unit or that top assembly on top of the prism? If so, what donors can I use? Quite a few cameras used the same 9 point AF arrangement, but I am sure in some the flexy PCB cables and connectors are different. On photos the 40d unit looked identical, but they used 9 point AF since the 20d, and in some later entry level models (500d?) if I remember correctly? I can solder if required, but would be nice to get away without! Depends on donor price of course.

    Unrelated: Sigma 28-70/2.8 EX (non DG), aperture sticks, “electronically”. Sometimes works well, but more often it stops down on 1st shot or DOF check, but would not open fully. Next shot (darker expo) closes further, and opens a bit again but even less than before, all the way until fully stopped down. Removing and reinstalling the lens normally resets the aperture to full 2.8. Took it apart, there seems to be no mechanical issue. There is an end switch to sense the 2.8 position (open at 2.8, closed anywhere else) and the mechanism is driven by a stepper motor, so I think it is open loop control apart from fully open 2.8. I tried to clear and adjust the switch (as thought the lens might think it opened the aperture when it didn’t), but no success whatsoever. Checked continuity, always worked as I’d think it should when taken apart. Any other clues? Am I missing something?

    Thanks in advance, and keep up the good work! 🙂


    • canonrepair says:

      1 i would use original shims, as i have them in the box 😊 if not, then some stickers, only on the sides.
      3 EACH used camera has to be disassemled and checked. They need to be cleaned anyway, and the loose screws can always appear.
      i would check the 40d af led–

      aperture control is ALWAYS open loop, older lenses with a mechanical switch, neewer with optocoupler. but can be a problem with the flex cable.

  113. Vladimir V says:

    Hi, I tried to write you, but it gave me error 😦
    Could you give me some hint about Canon 70-300 DO?
    I bought it used with oily aperture, actually that didn’t bother me, since I’m shooting wide open, and it was cheap. The pictures are overexposed in f/8 and smaller. Also my 500D didn’t show any error. I was thinking some day to replace the aperture (I don’t believe it is meaningful to try only to clean it), but there is something that bothers me – I did some tests with exposure, and it seems that overexposure is same for a set of aperture sizes. Here are the results:
    @70mm : (4.5,5,5.6,6.3) -ok, (7.1,8,9,10) +1ev,(11,13,14) +2ev,(16,18,20,22) +3ev,(25,29,32) +4ev
    @300mm : (5.6,6.3,7.1,8,9,10) – ok, (11,13) +1ev, (14,16,18,20) +2ev,(22,25)+3ev,(29,32,36,39) +4ev.
    If I set it manually @ -1ev, the picture is OK @ f/10. It is clearly visible that for example @f/10 the aperture is more closed than @f/11. Does this happens only if EMD is faulty, or it might be a problem with PCB?
    Another question – I found parts list, and EMD is “YG2-2098-000”, is it the same as “YG2-2098-009”? I could find only the second part as spare.
    Any hints will be highly appreciated 🙂

  114. bertus11 says:

    Hello Janos,
    I think I will keep the 5DmkII for myself, so there is no hurry in solving the problem,but perhaps it is a good idea to let you read out the error codes. What program do you use at the moment? Deamon Tools is no longer available. What would be the cost for replacing the mainboard or replacing the Cmos sensor?

    • canonrepair says:

      Daemon tools is OFFICIALLY not available – but I have a backup copy :). So with the SPT running on my PC we can read them out. The error-reading will be for You – but ONLY for You – for free.
      Case I have to replace a mainboard, the question is, if I can retrive the data from the old one, or not. If yes, then theoretically is not so difficult, the labour wold be 100 EUR. If not, that means a lot of work because the AF sensors. That would be 150 EUR. A used mainboard on the ebay is approx 200 USD (but I would NEVER buy from that source), a new one is about 400 USD from the USA.
      The CMOS needs anyway to be adjusted to the body, so that would be the labour 150 EUR.

  115. bertus11 says:

    Hello Janos,
    I haven’t reacted for some time, but I am still reading your blog.
    I have a stange problem with a 5D mkII. I already have the camera for several weeks,
    but the problem to me occurred only once, so it is difficult to investigate.
    Suddenly when taking pictures, the pictures where pink with a strange pattern in the
    upper part of the picture. I googled for this problem and found that several people had
    this problem and those who had send the camera in to Canon got a heavy bill for changing the motherboard.
    Did you ever see this problem?
    Changing the mainboard is quite an expensive solution for a problem that occurs incidently.

    You can find a picture here:!AvYEOBq8Mh_FgSvobS2DM-uihYKG

    Regards and greetings from The Netherlands,

    • canonrepair says:

      Hi Bert, I think this could be a cmos OR a mainboard problem too. I have here a used cmos (unfortunatelly with a laser damage), and a mainboard too. So case you decide to let the vcamera repaired, I could do it for You. I also have the SPT software for the 5dMk2. There is a possibliity to read out the error codes from the camera through the internet. Internal error codes could tell more of course.
      Case the problem comes back more often with the time, could be for ex a BGA chip soldering problem.

  116. Christian says:


    My 40D is not working. The symptoms are: clicking sound about three times when switching on, Err99 appears.
    I’ve removed the lens and the front body cover (around the bajonett) and saw the mirror got stuck. The clicking came from the right motor (the mirror motor), it turns about a 3/4 turn and stops without pressing the shutter, just by switching on.
    Do you know this problem? Is the mirror hinge or the main mirror driving motor broken?
    What shoud I do?
    Look at this picture from the mirror-shutter system for overview:

    Regards from Austria

    • canonrepair says:

      could be a mecahnical damage, a loose screw stucked somewhere, or a damaged phase sensor (which gives the position of the mirrror mechanism)

      • Filip says:

        Also it is possible that LV8013 motor driver on the bottom PCB is damaged (half dead).

  117. Thank you for this interesting blog!
    Ok, I have few questions for you. I have been repairing eos lenses and bodies several years now, but there is always something weird problems that I cannot solve.

    Here is the one:
    I have now two lenses, EF 24-105 4L and EF 100 2.8L IS USM (dropped). I got that EF 24-105 because it had broken aperture flex cable. I replaced it, but it still does not work: IS unit is making tickling noise when lens is attached to a body, and aperture value on upper LCD screen is flashing beetween f00 and f4.0 or so.
    I unplugged IS unit and aperture unit from main PCB, but it still keeps flashing aperture value when turned on.
    EF 100 2.8L IS has same problem. Previous owner had dropped it and said it wont focus anymore. Well, I plugged it to my body and immediately IS unit started keeping noise.. it sounds like it is trying to reset itself repeatedly. And at same time, again aperture value on upper LCD is blinking.
    So is it actually bad IS unit causing these
    phenomenons? Or in worst case, bad main PCB? 😦

    Best Regards,
    Toni Hallikas

  118. Bojan says:

    Yes, without proper schematic diagram, that is all that I can do at the moment.. Thanks 🙂

  119. Bojan says:

    Hi ,
    I have 400D with error99 problem. Already replaced faulty FET on Power board (it seems there was a short caused by detached pin from CF card connector that was wandering inside and that FET was dead when I obtained the camera from ebay)
    Symptoms at the moment:
    On pressing shutter button, it seems something is trying to move (motor?).. but there is no autofocus (no movement in lens), so I think the power to lens may be missing.
    Without lens, pressing shutter buttom al the way generates error99.
    I really need a wiring schematic diagram… does anybody have it? The information in manual downloadable from ElectroTanya is not sufficient..
    Thank you in advance!

    • canonrepair says:

      unfortunaltelly on the DC board die not only FETs but the IC too.
      At first I would search for a donor, and would try to find out through changing modules.

  120. Dorian Hargarten says:

    Hey! Thank you for your great blog! My question is: I have a Canon Eos 60D with around 117K shutter actuations according to Magic Lantern. So far, the camera works like a charm, but as I recently picked up timelapse photography, my shutter count has jumped quickly. I am wondering whether I should continue using this camera, or get a used Eos M Body to do timelapse with. I looked inside the lens bajonet of my 60D to see if there is some wear visible, but I can’t see anything. Are there any visible indicators of wear before a shutter dies? If the shutter dies, how expensive would the replacement be?

    • canonrepair says:

      there are no sign of a weared shutter. I have seen even 40d shutter with 225000 (!) actuations, and 40d with dead shutter after 8000 exposures.
      to see the shutter price go to the (USA). I normally change a shutter (only the labour) for approx 60-80 EUR, depending on the camera type.

  121. Kenji says:

    Hello Ruzsa,
    my Canon 5d Mark II has problems with the buttons on the back side.
    Only the small joystick and the display is working. All other buttons and the on/off switch don’t work.

  122. Poppy says:

    Hi, you have a very nice blog with excellent write-up here.
    I have a Canon 24 70mm f2.8 USM L lens. AF was okay but manual focus slip. I followed some online tutorials and attempted to repair. I rotated the silver retaining ring (face cam) to tighten it up a bit and manual focus is back to normal. However, AF is not behaving well. It became choppy and will not be able to focus sometimes. I opened up the lenses several times to adjust the tension but it just won’t work properly. The silver ring seems stuck and the USM rings and motor can’t be removed for cleaning. Have you had any experience repairing USM assembly ? I need your advice please.

    I followed these guides : ( to open up to the USM part) (step 10 and 11 for USM adjustment) (removing rings – but mine get stuck and can’t be removed)

    Hoping to hear from you soon.

  123. Dmitriy says:

    The dial on the back of my 6D is stuck – it is very difficult to turn. How can this be repaired? I am located in Budapest. Thanks!

  124. Jordan says:

    I got a 5D mk1 that is not booting and I’m trying to fix it. I replaced the LPU board as it was damaged, but still nothing when I switch the 5D ON (no LCD, no top screen, no effect when I press any button). I checked the power provided by the DC/DC board, 5D OFF I have VCH, V1.2, VO (VTFT, V2.5, CVBAT at 0v), 5D ON I have VCH, V1.2, v2.5, VO (VTFT, CVBAT at 0v). I expect one of the power to be down as I have maybe something dead on the board. Is it what we expect ? Are these 2 missing power mandatory to have the 5D lighting at least the top screen ?
    Do you know what is the boot sequence, who is driving what to powerup the device?
    Thanks in advance.

    • canonrepair says:

      hi,i cannot check this right now, but try to measure the fuse on the upper dc board, and the fuses on the other one lateral.

      • Jordan says:

        By “upper dc board” you mean the LPU board ? The 2 fuses are OK on this one, and the board should be fine as I just replaced it.
        And by “the other one lateral” you mean the DC/DC board ? The 4 fuses are OK on this one as well. It’s on this one that I was checking the power.
        Is there any other fuse on the other board that I can check ?

      • canonrepair says:

        in this case try to check ALL flex cables.

  125. Marek Madisoo says:

    Hello, i have an issue with 600D powerboard, i got new one, but i forgot to picture the wiring, do yo u have any pictures of that ?

    Thank you

    • canonrepair says:

      600d DC-DC board:
      on the board you have a part with the code “151”.
      around it, You will find 4 marked points for the cables:
      XB dark grey
      XG light grey
      TY yellow
      TW white

  126. Dirk says:

    Canon 6D err 20
    Recieved a Canon 6D with little water damage. lower board was short circuited at the small ribbon pcb where it connects to main PCB. Replaced bottum PCB and ribbon, tested the main PCB in other 6D and found all oke. still err 20. Suspecting shutter now. any idears?

  127. canonrepair says:

    This is very strange, as the bottom PCB is not so expensive. I tried once to repair it, as I observed, that some FET-s are blown on the damaged board, but after changing them it was the same situation. I had no ore time to make experiments, so at the moment I better change them to a new one.

    • Miguel Morgado says:

      Thanks for your reply. I’ll buy the board when I have the funds. Now I’m bracing with a cano 28-80mm l and a 80-200mm l with fungus… Good work

  128. Miguel Morgado says:

    Canon 7d
    Hello Janos! I’m writing to you from Portugal. I’m sort of in the same business as you, the difference is that I buy broken material, repair it and sell. Just as a hobby. Recently I bought a broken canon 7d which the owner had already diagnosed in a canon repair center a faulty bottom board, due to the infamous loose screw. They wanted to replace the board, but that was too expensive. What I want to ask you is if you have already repaired any board with this failure or is a time waste and it’s better to replace with a new one. Thank you very much, Miguel.

  129. aaf says:


    about lens board controller (the PCB) would you share if you have found problem about lens main board and about solving problem, thanks a lot…

  130. prashant m pasarkar says:

    Canon 1000d
    In viwfindar bizzy err shows lcd dosnot on …..

  131. Laampalamu says:

    Canon EOS 350D, plate?

  132. Laampalamu says:

    There’s a Q component in top right corner, do you know what is it? Mine has burned up.

  133. Kdbcz says:

    Csak általánosan: ha van egy gép amelyiken az autofókusz pontatlan, hogyan állapítható meg, hogy mi ment el, sensor, tükör stb., vagy lényegtelen, utána állítanak szovtveresen és kész?

    • canonrepair says:

      osszuk több részre a kérdést:
      – ha az AF mindig AZONOS módon téved (backfókusz, frontfókusz), akkor:
      – ha előzőleg szerelték, akkor a cmost kell előbb helyretenni, utána jöhet a szoftveres állítás (bár nekem sikerült már csak mechanikusan is helyretenni, de az nem általános)
      – ha csak a kopásoktól, akkor elég a szoftveres állítás
      – ha összevissza fókuszolt, akkor általában a tükörmechanika mozog, lóg – ilyenkor előbb azt kell megjavítani, csak utána érdemkes beállítani

  134. Chris says:

    I have been reading your material for over a year and it has been extremely helpful. Thanks for all your time in sharing your experience and knowledge.

    I am planning my first CMOS swap in a 40D. This has always given me some anxiety due to the FFD adjustment.

    I read your blog from December 30 2012 in which you describe the procedure you use. It all makes sense to me, and the only question I have relates to the measuring bench you constructed.

    What is the steel plate you obtained from the transfer pump used for? It appears to be fastened to the brake rotor and I assume the camera fits on to this plate to keep it from moving while taking measurements?

    As you need to constantly move the camera to take different readings, I cant figure out the purpose of this steel plate. I was just going to rest the camera’s lens mount on the rotor and slide it around when needed.

    Thanks in advance.

    • canonrepair says:

      hi Chris, the steel plate is the measuring base. the camera will be hold on the surface just by pressing it down, and HAS TO MOVE IN ANY DIRECTION in that plane, as the measuring points will be in different places.

      • Chris says:

        What is that other cylindrical metal component sitting on the rotor in one of the photos? I originally thought it was a machined part which mated with the lens mount to secure the camera to the base (brake rotor). As the camera needs to slide on the rotor surface, this components function has me perplexed.

        Sorry, I couldnt figure out how to attach a photo for clearer reference

      • canonrepair says:

        That is just an aluminium cylinder (could be of any other metal), just to hold higher the steel plate, because the camera has the flash and the handle in the front, which should have enough space, when the camera is on the steel plate. This is fixed to the brake disc, and the steel to the aluminium cylinder.

  135. Jonny says:

    Canon EOS 5D Mark I

    Hi there!
    I tried to repair my girlfriends 5D Mark I, which gave no sign of life after she used it the winter one year ago. I assume she just kept the camera in a warm room after using it out in the cold. At least I found some water stains close to fuse on the LPU-Board when I tried to repair it two month ago. So I already replaced the blown fuse close on the LPU-Board, but still no reaction when I switched it on. The next disassembling showed that the fuse was still well, so I checked for more errors and I found a second blown fuse on the DC/DC-Board. I’ve reassembled the camera but still no reaction.

    Few days ago I’ve checked the power consumption as explained in the service manual and if I remember right, the current was around 350uA (100uA is told for locked state, 150mA is told for standby) I’ve checked to fuse on the LPU-Board which is still ok.

    I could check the fuses again on the DC/DC board again, but for me it’s still a big thing to disassemble the whole camera. I’m going to do this at my work, so it’s better to know what to do, to find possible errors or to find out which PCB is broken. I’m a trainee and I can use my company’s oscilloscope, soldering irons,…

    I understand the circuit diagrams so I could measure the voltages at different points, to find the error. But I don’t know how to safely turn on the camera if I’ve disassembled parts of it, without stressing the cables.

    Maybe you have an idea what’s causing to problem or how I can do further researches to find the error.

    Best wishes,

    • canonrepair says:

      Canon EOS 5D Mark I
      a tfirst, check the flat cable between the PCB C and PCB D (the two big main PCB-s. This cable you can mount in 4 positions – and only one is good…
      if no sign of life after trying this, then probably the dc dc board is blown (the fuse cannot always save the electronic parts). it would be great to have a donor, for a quick check..
      to start the camera disassembled you have to block the switches under the battery door and under the CF card door.

      • Jonny says:

        thank you for your help so far!
        The cable between PCB C and PCB D was in correct possion, but the fuse F101 on the DC/DC-PCB, that I already changed, was blown again. I’m not sure if the main controller on the DCDC board is still working, but the MOSFETs of the buck regulators still seem ok and there is no short circuit to ground. I apllied 9V on the V_BAT connector to measure the different voltage levels the PCB should provide, to see if only the two voltage regulators, that are protected by the blown fuse, are broken or if the whole board is defect. Anyhow, there was no real power consumption and I wasn’t abled to measure any voltages on the board. Maybe I have to put load resitors to the different voltage outputs but I assume that the board only works, when it’s connected to other PCBs.
        I also measured the resistance from V0 and V2.5 to ground on the D-PCB, which didn’t indicate a short circuit as well.
        V0 and V2.5 are used by System-Block and for the Logic of the TFT Panel, but I still don’t know which PCB is blowing the fuse. Do you have an idea what could cause my problem or do you have a donor for 5D Mark I parts so i can send you the camera for checking and repair?
        Best wishes,

  136. Jonny says:

    Canon EOS 5D Mark I

    Hi there!
    I tried to repair my girlfriends 5D Mark I, which gave no sign of life after she used it last winter. I assume she just kept the camera in a warm room after using it out in the cold. At least I found some water stains close to fuse on the LPU-Board when I tried to repair it two month ago. So I already replaced the blown fuse close on the LPU-Board, but still no reaction when I switched it on. The next disassembling showed that the fuse was still well, so I checked for more errors and I found a second blown fuse on the DC/DC-Board. I’ve reassembled the camera but still no reaction.

    Few days ago I’ve checked the power consumption as explained in the service manual and if I remember right, the current was around 300uA (100mA is named for locked state, 150mA is named for standby) I’ve checked to fuse on the LPU-Board which is still ok.

    I could check the fuses again on the DC/DC board again, but for me it’s still a big thing to disassemble the whole camera. I’m going to do this at my work, so it’s better to know what to do, to find possible errors or to find out which PCB is broken. I’m a trainee and I can use my company’s oscilloscope, soldering irons,…

    I understand the circuit diagrams so I could measure the voltages at different points, to find the error. But I don’t know how to safely turn on the camera if I’ve disassembled parts of it, without stressing the cables.

    Maybe you have an idea what’s causing to problem or how I can do further researches to find the error.

    Best wishes,

  137. KK says:

    I have a friend that bought a replacement LCD display for his Canon 7D. Installed the new screen, and when the camera was powered on, the display was very dim. After cycling power a couple of times, the camera now gives Err 40. Besides a new LCD screen, any guesses if the issue is the bottom Flash PCB, or the DC/DC PCB above the battery chamber? I am guessing a fuse blew, but I am pretty sure you cannot buy fuses for the 7D.

    • canonrepair says:

      at first, try to check the bottom PCB.

    • Jonny says:

      It’s possible. You just have to check for the letter on it. I guess I bought some of these:
      or another one thats similar. But Schurter is using the same system with letters to name there fuses as canon does. You also should check for the size. 0603 is used in 5D Mark I but I’m not shure if the use the same package for 7D.

    • Jonny says:

      It’s possible to buy them. I bought two different fuses from schurter for a canon 5D.
      Not every manufacturer of fuses uses the letter system schurter and the supplier of canon are using, to specify their fuses. If you’ve found the blown fuse, check for the letter on it and look for that letter in the datasheet, it stands for the rated current of the fuse. The size (package) of the fuses in the 5D is 0603 and I guess it will be the same for 7D. With these two information, it should be possible to find a distributor, how is selling small amounts of the fuses you need.

      • Kenny K says:

        The problem ended up being that when my friend put the camera back together, he did not record where every screw came from. This resulted in a screw that was too long being used on the bottom, which dug into the cable from the Main PCB to the Bottom PCB. I also located one of the bottom PCB screws stuck to a piece of tape under the top housing. It works great now, no fuses needed replacing.

  138. Filip Lolic says:

    Hi Janos,
    I know this is blog about Canon equipment, but do you have any experience with Sigma lenses (for Canon)?
    I am trying to disassemble Sigma 12-24mm f4.5-5.6 DG HSM lens but I am stuck in the middle and don’t know how to continue… 😦
    The problem is, I don’t know how to remove “baffle ring” from the front side. Behind it there are 4 screws that I have to unscrew in order to proceed.
    I don’t know if that ring is screwed, glued or fixed with some clips, and I am afraid to apply force not to break something. I tried few tricks but that thing does not move at all. Can you help? 🙂
    I am talking about this:


    • canonrepair says:

      sorry, I missed this comment somehow.
      So, the rings can be fixed in different ways: with adhesive tape, with the filters thread, or simly with some plastic pins, whih are perpendicular on the rings urface, and are pressed on some holes in the front element.
      In the second case You can use a cilindric object with the same outer diameter as the inner diameter of the lens, with a ring formed piece of rubber (form an old car tyre, or from a coffee machine sealing etc), which will work as a friction-surfase. You have then to press and rotate simultanuosly.
      In te third case yust a small flat screwdriver….

      • Filip says:

        Thanks Janos 😉
        I tried to pry it with small flat screwdriver but it does not move at all. It is most likely threaded. I will try to make suitable tool on my lathe, hopefully I will manage to unscrew it…

  139. Tunde Szabo says:

    Kedves Janos!

    Segitseget szeretnem kerni! Canon eos 30D gepem ma akkutoltes utan bekapcsolt, kerte a datumbeallitast, az ev es honap kivalasztasa utan elsotetult az lcd kijelzo, majd magatol exponalt 2t, a felso kijelzon az err99 jelent meg es azota nem kapcsol be.
    Az aksijat a tolto feltolti, behelyezes utan a leptetotarcsa melletti kis kijelzo pirosan vilagitott, de masodszori behelyezes utan mar az sem.
    A canon honlap javaslatara letoroltem az objektivek erzekeloit, az aksit is megtorolgettem, cf kartyat csereltem, de semmire sem reagal 😦
    Tudna esetleg valami megoldast javasolni vagy esetleg hibajavitast tanacsolni, hogy mi lehet a problema?

    Valaszat elore is halasan koszonom!
    Szabo Tunde

    • canonrepair says:

      Kedves Tünde,
      nem használt vele véletlenül chippel ellátott manuális optikát? Ilyen hibát okozhat pl a táppanel meghibásodása, vagy a gép beázása, de éppenséggel egy, a gép belsejében kiesett csavar is. nyilván szét kell szedni egy rendes diagnózishoz.

  140. Ben says:

    Thanks man. I am going to send you some shots now.


  141. Ben says:

    Hi Ruzsa,

    Great site. I have found some very useful info on here. Much appreciated. I have a question if you have any experience, or can offer some suggestions on how I should proceed with a Canon 28-70 L F2.8 that has back focus issues, and the focus is never really tack sharp, unless maybe if the subject is very close. I did some adjusting to minimize the chromatic aberration after following some information on here regarding another lens. I think I improved the state of the lens, but it is still too soft. Any suggestions would be great.

    Thank you,


  142. Seppo Rinta-Kauppila says:

    Hi! Thanks for youd note.

    I do not actually know that is wrong with the lens. Manual focus seems ok. Mecanically and cosmetically the lens is in fair condition. Activating IS makes some noises and the lens gives Err01 after shutter 5D.
    I suppose this might be the infamous flex cable issue?

    I bought the lens very cheaply from a second hand shop with a note ‘not working’ – now knowledge whatsoever about the previous history of the lens.

    I’d be glad if you accept the lens for inspection and eventual repair.

    How do we arrange the payment?

    Seppo RK

  143. Seppo Rinta-Kauppila says:

    I’d need your help with Canon 24-105 Err01 – can I send the lens to you for repair?
    Could you contact me for more details please.

  144. Per says:

    Hi Janos,

    Thanks for all information and knowledge you are sharing with us.
    I have some lenses I have trouble repairing.

    EF 50mm f1,4 is badly front focus.
    I found your tips but my board doesn’t have the adjustment solder-pads, older or newer?
    Is it only adjustable by software?

    EF 16-35mm f2,8L not sharp.
    I purchased it broken after a floordropp.
    I changed the barrel and focus motor and its almost 100%, but I have trouble adjusting the rear lens. I move it in small portions and then try to look at the photos.
    Do you have any tips or tricks for that lens?

    As a happy hobby Canon photographer (50D, 1Ds II, 5D III) I have a lot of things but no software like the SPT. I still think its expensive but I have a question.
    If buying the 50D (essential) can I attach different lenses on that body and correct the focus for each lens or will the adjustment only “stay” in the house?


    • canonrepair says:

      1 only through software
      2 if you have a reversing ring, use it as a macro lens reversed. the picture quality is the best reversed exactly then, when in normal position. and do the adjustment in liveview with a monitor.
      3 adjustments are done in the camera, not in the lens

  145. Kenji says:

    Hello Janos,
    thank you for sharing your knowledge with us!
    I jsut wanted to know if it is possible to replace a 5d mkii main board with a used one.
    Did it work instantly or did it need initialization?

    • canonrepair says:

      hi, it will work, but the shutter timing will be bad at higher speeds, AF will be absolutely wrong, and probably the exposure meter too.
      Without service software the replacement has no sense.

  146. canonrepair says:

    I had never enough time to compare a good and bad camera, so I always changed the board.

  147. Kk says:

    Do you have any of the specs on the fuses for the canon 7d? Or a link to where they can be ordered from? Thanks

    • canonrepair says:

      why, do You know, where the fuses are??? Beacause till yet i didn’t found them. I think they are no fuses in the 7d, just current limiting, and when something makes a real short (a screw), the DC-board (mainly the lower one) burns out. I have seen till now 4 such cases…

      • KK says:

        I contacted a US Canon parts distributor on which of the Canon fuses I should purchase for the DC/DC board. I was told that Canon does not list the fuses for the 7D seperately, they only sell the board as an assembly. Have you found the part that dies on the lower DC (flash) board when the screw gets loose? Or is it just easier to replace the whole board?

  148. OH says:

    Send me some more info!

  149. OH says:

    I have 3 Canon 40D cameras.
    One of the have a focus problem, When i try to focus on something it “hunts” and don`t lock focus.
    It happens in full auto and in p, tv, av, m mode. It`s a little bit better using single point / center focus.
    When i try to zoom a bit or move around it can suddenly focus.
    I have tried with 3 lenses and it`s the same. they work perfect on the other 2 cameras.

    Here`s a little video of the problem:

  150. Csilla says:

    Szia! Van egy canon 50mm f/1.8 as obim. A probléma az hogy egyszerűen akárhogyan állítom be a fokuszpontot a képek nem élesek meg f 4 nel is csak alig van javulás. Mit lehet vele kezdeni. Tudom ennyi penzertcnem minőség van. De a kép lehetne éles… Előre is köszönöm válaszod.

    • canonrepair says:

      Szia, az 50mm F1,8 mecahnikailag valóban nem egy csúcskonstrukció – a képének azonban nagyon jónak kell lennie. Ha mégsem az, akkor vagy nincs fókuszban (akármit jelezzen is vissza az AF rendszer), vagy pedig szétesett az egyik összetett lencsetag. Az elsőt egy Liveview-s géppel tudod ellenőrizni. A másodikhoz szét kell szedni az optikát. Ez utóbbi esetben kb 4-5000 forintos javítási költséggel kell számolnod.

  151. Hello,
    I dropped my 5d mkii and afterwards it worked briefly (for a minute or so). Then when I checked again it didn’t. The lcd screen shows only a mash of dense gray lines and there is nothing on the top screen. The mirror opens and closes when pushing the shutter but nothing else happens. The eos utility can see the camera, but when I try to take a photo this way, I only get a magenta/gray mash.
    Any ideas? I will also pass by Budapest in 10 days, would you be willing to take a look?

    • canonrepair says:

      Hi Luka,

      it’s hard to say anything without seeing the camera. If You are here, you can bring here the camera, but I need 1-2 days to check it. Can be that you have problem only with a flex cable – but I can say this only after disassembling it. You can have a broken shutter motor too. Write me on email, If you know your schedule.
      ruzsa.janos at

  152. OH says:

    Have you had any Canon 550d / Rebel T2i With battery problems?
    The battery drains very quick,
    Canon wants to change the battery box in the camera and do some adjusting (€360).
    I can get a battery box on ebay from €12, but what adjusting can they do?

    • canonrepair says:

      I think they don’t change ONLY the battery box, but the battery bow AND the DC-DC circuit (which is definitelly not 12 EUR) . In that case, theoretically You have to make a calibration of one PCB to the others. Or they make the setup for the lowest acceptable battery voltage.
      No other ideea.

  153. Zoran Simin says:

    I bought 24-70/2.8 II and have a problem with focus on my 5dmkII. Focus is not consistent, sometimes is correct sometimes I have back sometime front focus. With 5dmkIII is working perfect.With old 24-105 and with 100macro L and 135/2 5dmkII works fine.I had similar problems in past with some lenses like 35/1.4L.Do anyone have same problems?

    • canonrepair says:

      1 try with another 5dMk2 too
      2 always make separate tests for vertical and horizoltal targets (black line on white surface). I remember, I had once a 5dMk2 camera with a very big difference between th e two sensors – ca. 5 cm on 1 meter!
      This could mean, if you make a picture, and unfortunatelly the target ha a vertical line, the focus will be setting in another place, than in case of a horizontal line.
      in the camera the AF processor (or what) decidese AUTOMATICALLY, which AF sensor to use. (not the AF point. Behind each AF point you could have more sensors, for ex F2.8 sensors and F5.6 sensors, vertically, horizontally or even at 45 degrees.

  154. Ryan says:

    So the essential software doesn’t copy shutter settings? What would you charge to to the fix remotely? At the moment I am just repairing cameras for myself, but depending on how it goes i may do repairs for others as well.

  155. Ryan says:

    I have a 40d that i had to replace the main board in. I used the spt software (essential version) to copy data from the old board to the new board (old board had damaged pads for cf slot). Everything works except high shutter speeds (over 1/2500). Wondering if this is a shutter issue or a config issue that needs the advanced software.


    • canonrepair says:

      it’s the shutters normal behaviour, as all shutter have different curtain speeds, that means, curtain 1 and curtain 2 will run with different speeds and different delays. This is corrected from the software with different starting moments of the second curtain. As You couldn’t ccopy the timing value, You have this problem. There are 2 possiblilities: we can connect Your camera to my computer through the internet, and I can set up this remotely (this has a certain fee), or You can try to adjust the speed of the curtain with the pretensioning of the spring (this is for free of course :)).

      regards, János

    • canonrepair says:

      and yes, needs the adwanced software. do You repair only Your own camera, or You repair for others too?

  156. Hello,
    I have a problem with an old Cannon EOS 20D digital camera.
    Recently the camera can`t raise the main and secondary mirror all the way up and because of that the mirror casts shadows when shooting. Is there a way to solve this problem?

    • canonrepair says:

      Hi Milan. I’m sure it is possible to solve the problem – but for that You have to disassemble the whole camera. I could do it, and a repair is about 40-50 EUR. The question is, where do You live, does it have sense to send it through post or not?

      • Hi, thank you for the quick reply. Since I live in Serbia it isn’t recommended to send the camera because of the customs taxes. Have you seen such malfunctions before and is the problem in the spring or is something else the matter with it? Thank you in advance.

      • canonrepair says:

        I have seen something like this, but not on the 20d.
        In fact the mirror, as I know is moved upwards by a spring, and forced down by the mechanism. It could be, that Your spring is damaged, or, more possible, that You have something betwenn the spring aand the body or mirror. I have seen such a case with a screw, which blocked the mirror.
        There is no other way than disassembling the camera.
        Thera are some difficult points there, like: after taking out the screws from the back cover, be careful nor to tear of the flex cables. Or, as You will have to take out the sensor to get access to the shutter and mirror, You have to take out the shims from the sensor – be careful, there are different! The best is, after taking out the 3 screws and lifting the sensor to PUT BACK the 3 shims and the screws, and You will not swap them.
        And MAKE DRAWINGS (skethes) during disassembly – they are better then only taking photos.
        Good luck!
        What are You photographing?

  157. bertus11 says:

    Also Canon 40D.
    I have an other Canon 40D with a problem. The hinge on one side of the mirror is broken. Do you know if the mirror of a 30D is interchangeble, or does anybody know where to buy a 40D mirror?

  158. bertus11 says:

    Canon 40D.
    I have a Canon 40D with error 99. It has some strange shutter behaviour. Taking a picture gives an error 99. In live-view, the mirror comes up and the shutter opens, so I can see the sensor. Taking a picture now also gives an error 99.
    When I go to manual sensor cleaning, the mirror comes up, the shutter opens, but immediately closes again and the mirror comes back to standard position.
    Do you think the shutter is causing this problems?

    • canonrepair says:

      I think this is the typical 40d and 50d shutter problem. I had a camera recently (a 50d) with the same symptome. I changed the shutter to a used one, an dnow is perfect. I studied the shutter, but it was nothing to see. No interrupted solenoid, no mechanical problems. I think that it must be a problem with the shape of the cam which operates the curtains, I think it wears after a small numbers of actuations, and the mecanics engages the shutting of the second curtain before the solenoid is holdin git. but this is only a theoretical possibility.
      Just change the shutter.

  159. doragyula says:

    Kedves János!
    Egy 600D váz kártyaolvasója miatt kérnék segítséget. Egyszer csak elkezdte kiírni “A kártya írásvédett” bármilyen kártyát is teszek be, azaz nem tudok fotózni vele…
    A baj, hogy Indonézia műszakilag kevésbé felszerelt végében vagyok még 2 hétig, és nagyon kéne vele valamit kezdenem, mert a munkámhoz tartozik, hogy fotókat készítsek az ittlétem alatt. Talán tudok szerezni egy-két kisebb csavarhúzót, de a megbontáshoz is kéne némi segítség, rajz, utasítás.
    Ha tudnál segíteni, nagyon szépen megköszönném…

    Szép napot neked!

    • doragyula says:

      Itt – is – szeretnék köszönetet mondani azért, hogy Indonéziában meghibásodott gépem hazajutásában, táv-megjavításában és visszajuttatásában segítettél nekem. Azt gondolom, hogy mindenkinek tudnia kell azt a tényt, hogy én nem csak egy “javítást” kaptam, hanem egy igazi együttérzéssel és emberséggel kezelt helyzetmegoldást is.

      János! Köszönöm Neked!

      Tisztelettel egy nagyon elégedett fotós,
      Dora Gyula

  160. JC says:

    I have a dead 7D and am going to disassemble to check the P and K fuses which you report are often dead. You also mention in a 5D blown fuse page to measure the resistance between gnd and plus. Can I ask how?
    And also how big of a task is it to get to the DC board?

    • canonrepair says:

      At first try to check the battery. The 7d has an idiot battery type, which can make bad contact with the body. I disassembled a few weeks ao this camera – and after finding nothing in the inside, I realised, that the only problem was the battery….

    • canonrepair says:

      “The DC-board had a resistance of 2 ohms between the plus and the GND…..” Take an ohmmeter, and measure resistance WITHOUT the battery. Thats all.

      • JC says:

        Thanks for the quick reply. I shall get an alternate battery and report back!

      • canonrepair says:

        The problem is not necessarily with the battery. Could be the 2 contacts from the camera too.
        After disassembling the body, push in the battery and then measure the VOLTAGE on the DC board. Or try to push and pull the battery many times.
        If on the DC board appears the battery oltage, then the problem could be on the board, fuse etc.

  161. Erik says:

    Canon 50d

    Hello, I’m trying to repair a 50d that sustained water damage. Body is completely dry, and I’ve cleaned all corrosion I can find. When a battery is inserted nothing happens — no lights, motors do not move; and switching the unit on does nothing either. I suspect the dc/dc board as this was the most corroded and plugging power to this board alone gives no voltage difference on the pins which would connect the dc/dc board to the main board. There is a smd component labelled “JB 9K3” that is in an 8-pin smic package that is open (no conduction) which I think is the problem, since another identical component has a resistance of about 8 ohms. Given the number of pins, I think the component must be more than just a resistor, but I have been unable to find a description online. Do you know of any way to ID the components on the dc/dc board? And does my diagnosis sound ok? I’m planning on buying a new dc/dc board, but don’t want to waste $$ needlessly. Is there any way you know of to test the dc/dc board? Thanks! Love the blog.

    • canonrepair says:

      after a water damage is difficult to save a camera. You should test a the cameras board in a functional body – but it’s risky for the good camera too. 50d and 40d have identical componenets too. could be that the difference is only in some connectors, and it is easier to find a donor 40d

    • canonrepair says:

      what abou t the bottom flash/DC board?
      that is important too.

      • Erik says:

        Thanks for the reply. The bottom board seems to be in better shape, but I have know way of knowing for sure. I have a working 40d, but am not sure if I want to try a board swap since it may damage the 40d like you said. With water damage, is corrosion usually the cause of problems? The component on the dc/dc board I think is bad doesn’t look corroded at all… I may just try my luck with a new dc/dc board since they’re only $50, but I guess there’s a good chance another board is bad too.

      • canonrepair says:

        check the big flex cable between the flash board and the main board. It is in a very unfavorable location, can get corrosion easily. If it is damaged, you can not turn on the camera.

  162. Anupreet Saluja says:

    Hey, My Canon Power Shot SX150 IS is giving lens error after I dropped it. I would like to drop it for repair. Please provide the address of your shop in Budapest.


  163. Paveszka Sándor says:

    Kedves János.
    Van egy EOS 7D gépvázam. Az a probléma vele, hogy a szenzoron található két pici kosz (két pötty) ami rekesz zárásra egyre intenzívebben látszik a képeken. C. kft szerint a gép beázott, ezért szét sem szedték, mert állítólag így nem érdemes… A váz hibátlanul működik, de állítólag a szűrő és a szenzor között van a két kosz. Az lenne a kérdésem, hogy vállalnád-e a tisztítását így a szenzornak, és a gépnek. Valamint, a fent említett kft által cserélhetetlennek ítélt mattüveg cseréjét is vállalnád-e?
    Előre is köszönöm a választ.
    Paveszka Sándor

    • canonrepair says:

      Nos, ha nem szedték szét, azt valószínűleg azért tették, mert ha eddig nem szakadt meg rajta valami, akkor egy szétszedés alkalmával akár megtörténhet.
      Ettől még persze érdemes – én biztosan megbolondulnék, ha az összes képen ott éktelenkedne egy folt. A fentiek figyelembe vételével (vagyis hogy esetleg totál halott lesz utána a váz) természetesen vállalom a javítást.
      A mattüveget nem egészen értem, hogy jön ide – azt miért kellene cserélni? Amúgy meg valahogyan biztosan lehet

      • Paveszka Sándor says:

        Magát a gépet szétszedték, tehát a burkolatot levették róla, csak tovább nem mentek, a szenzorhoz nem nyúltak. A mattüveg cseréjére azért lenne szükség, mert állítólag karcos. Igazából tisztíttatni vittem be a gépet, azt a véleményt adták, hogy nem gazdaságos a javítása, mert beázás nyomok vannak rajta. A mattüveg szerintük nem poros hanem karcos, de mivel mindennemű javítást gazdaságtalannak ítéltek, ezért az is maradt úgy, ahogy van.
        Örülnék, ha megnéznéd, véleményeznéd a vázat, ha rajtuk kívül te is azt mondod, hogy nem gazdaságos a javítása, belenyugszom, hogy minden képről le kell photoshoppolni a két foltot, de azért (mivel a gép hibátlanul működik azóta is) nem szeretném így lekukázni.
        Egy hozzávetőeleges időt tudnál mondani amennyit igénybe venne a diagnózis, és a tisztítás, ha mégsem reménytelen a dolog?

  164. canonrepair says:

    It is interesting, it seems that the camera cannot communicate with the lens – athought he recognized, that there is a lens on the mount. If the camera was never repaired, You should check if there is any flex cable loose in the socket in the inside. if You have no experience with repair, better to give it to somebody to do it. One month ago i was in Your city, in Iasi.
    8daca vrei, poti sa scrii si pe romaneste si prin email)

    • Catalin says:

      Cel de la care am luat aparatul l-a folosit cu un Sigma 18-200mm. Mă gândesc că probabil fiind asa mare “plaja focala” a obiectivului consuma ceva curent si la focus si sa nu se fi dus vreo banda flex din montura. Cu obiective M42 aparatul merge perfect.
      O sa continuam discutia prin mail.
      PS: am incercat acum cateva luni sa desfac aparatul , am desfacut toate suruburile insa nu am reusit sa il desfac pe cel de sub grip si n-am reusit sa dau plasticul din fata jos pentru a vedea care e treaba.

      • Catalin says:

        Va rog sa-mi scrieti un mail pentru ca nu reusesc sa gasesc adresa dumneavoastra pe site. Multumesc.

      • canonrepair says:

        mmmda, asta e frumusetea meseriei.
        sunt cazuri, cand proprietarii ar lesina, daca ar vedea ce forta trebuie scoase unele suruburi.
        plus numai scule de calitate. daca ai ratat un surub, si ai distrus capul, nu existata a doua incercare, doar burghiul si flexul miniatur.

  165. Catalin says:

    I`m having a Canon 450D which gives ERR01. If I tape the lens contacts , the camera works wonderful in Manual mode (I have a full manual old M42 lens). From what I heard it seems that a flex cable or something like that is broken. Is this correctly?
    Someone told me that the problem is related to the mirror-box. If I replace it will the camera work as it should?

    • canonrepair says:

      I cannot understand You 100%.
      does the camera not work with normal Canon EF lenses, and giving error ERR01?
      If Yes, the problem can be with the lens or the camera – mainly the lens flex cable is the problem.

      • Catalin says:

        No. The camera gives ERR01 with any kind of lens. I tried few 18-55mm and with all I get ERR01. But if I use an EOS-M42 adapter , my camera works flawless.
        PS: Flash not working either – shows BUSY all the time.

  166. Agi Frater says:

    Kedves János, már 2 Canon gépünk adta be a kulcsot. Az első egy PowerShot A70-es, a képen csíkok keletkeztek, először csak időnként, a végén pedig Karácsony előtt 2 nappal – már nem lehetett vele fényképezni. Kénytelen voltam venni egy másik gépet – ugye ünnep – PowerShot A590IS-re esett a választás, most lesz 5 éve. Lányom toszkánai útjának 2. napján nem nyílt ki az optika. Kénytelen volt az okostelefonjával fotózni az út alatt. Elvittem javítóba, teljes optika cserét mondtak 18 ezer+mdíj. Nem hagytam ott. Valami kicsi fogaskerekei darálódtak le, azt mondták. Van-e olcsóbb javítási lehetőség (remény), vagy megint vegyünk egy új kamerát? Megjegyzem, mr nincs bizalmam a Canonhoz.

    • canonrepair says:

      Kedves Ági,
      sajnos ezeket a kompakt gépeket alapvetően nem az örökkévalóságnak tervezték, sem pedig javíthatóra.
      Én nem is szívesen javítok ilyeneket. Sokkal jobban járnának, ha vásárolnának egy rendes tükörreflexes gépet – teljesen más világ. használtan pedig nem is megfizethetetlen – persze ha megbízható a forrás

  167. I can’t find such a gauge… Can you give me a link from where to buy it?

  168. Hi. I have Canon 500D and the body makes massive backfocus with any lenses that works fine on other bodies. I put main board on other 500D body and same thing – backfocus. Can you tell me how to adjust focus point by software or what you think about this problem? Back focus is appear on both AF and MF. On liveview mode is OK. Thanks in advance.

    • canonrepair says:

      I think Your camera was disassembled before to deep – I mean, somebody has taken out the cmos (the sensor) too.
      By this camera – and a lot of new types – this is not possible, because the cmos is adjusted with the 3 screws, NOT with the shims.
      Afterm assembling it back Your AF sensor and your matte screen are in the original position – but the sensor not.
      Don’t put a mainboard from another body to a camera if you don’t have a servisce software – AF will not work correctly.

      So, If You focus with AF or with the manual method, the picture will be sharp in the original position – but the sensor is not there.
      See this:
      It’s not easy to adjust, as You will need a measuring stand, and to make some calculations too.
      If You can send me the camera, I can adjust it for you, but I’m afraid sending it to Hungary would be more expensive, than my fee.
      Or, build Your own stand – shortly i will put the calculations on my homepage.

    • canonrepair says:

      where are You from?

      • I’m from Bulgaria. I will try to make measuring stand but i must to wait for those calculations you say. I’m very glad for fast response and for your advices.

      • canonrepair says:

        Do the measuring stand, I will help You with the calculation, don’t worry. You can see from the site, how it should be made. Important is a dgital measuring gauge with 1/1000 mm resolution.

  169. aaf says:

    Hi again,

    do you know about the source of Tamron sparepart store…. I need some items according to difragma motor problem, the motor is frozen, not move and the motor is hot, thanks in advance.

  170. aaf says:

    also have 2 unit of EF 16-35 here, the 2 lens fall and the mounting broke, after fix the mount… the AF is not work and the USM not move at all… anyone face the USM problems and what cause this symptoms…… grrrrrr…..

  171. aaf says:

    I have a EFS 17-85 and the USM not move at all, buy the new one focusing unit and still the USM not move… is the problem came from the mother board or else? thanks in advance….

    • canonrepair says:

      I have repaired once a 17-55 (not the same, but also a Canon lens), which case the stabiliser was not connected, has no aperture control (only in one sense – in closing), and with the bad position sensor (the metal comb on the barrel) has n autofocus moving.
      So, by this lenses failer in one part of he lens can cause a problem in the functioning of the other. Of course in such cases the easiest would be to check with a donor. Where do You live? I have a 17-85 now on my desktop – with only aperture flecable failure.
      Or sell me the bad 17-85 in this form.

  172. Pontosan ! A hiba stimmel ! Ha maxra allitom blokkol ! Ha csak megkozelittem akkor addig mukodik ! Szoval csak a maxnal blokkol. Szivesen elvinnem, csak Nagyvaradi vagyok !
    Hova kellene vigyem, vagy esetleg kuldenem ?

  173. Hello, nagyon praktikus az oldalad, gratula ! Probaltam keresni a problemamra egy valaszt, de nem talaltam, pedig biztosan letezik. Roviden 40D, error 01, lencse nem kommunikal a geppel.
    Allandoan fokuszalgat, majd leblokkol. Objektiv 17-85 alap objektiv. Tulajdonkeppen hol megy, hol nem, nehe tudok vele dolgozni majd egyszercsak bekattan, es kesz ! Szoval hol megy hol nem ! Egyebkent minden mas tokeletesen mukodik.

    • canonrepair says:

      szia, pedig ez elég gyakori hibája a 17-85 optikának. megtörik benne a szalagkábel, de mivel nem szakad el teljesen, bizonyos állásokban még működik, illetve, ha nem kell rekeszelnie az optikának, mert maximális nyitásnál ahsználod, akkor nem jelez hibás működést.
      próbáld ki, hogy tekerd az optikát 17mm ill 85 mm állásba, majd rekeszelj le , pl 16-ra, majd nyomd meg a blendebeugrató gombot a gép oldalán. az egyik végállásban már nem fog működni.
      ha ez a baja, nálam pl 13000 forintért javítható.

  174. rivera says:

    Helló, tanácsot szeretnék kérni: van egy Canon 35L 1.4-es objektívem, amin a fókuszgyűrű gumi borítása (nem tudom mi a hivatalos neve) meglazult, lötyög. Használatban nem zavaró, de eszétikailag, illetve a tudat hogy nem tökéletes zavar. Házi DIY módszerrel meg lehet ezt javítani? Arra gondoltam hogy csöppentek alá 1-1 csepp pillanatragasztót két oldalt, de nem merem kérdés nélkül megtenni. Köszönöm, r

  175. Aaron Adler says:

    Hello! Great blog!
    I recently took apart my old L Series 17-35mm Canon lens because a screw had come loose inside and was bouncing around inside the body. I took apart the body and and found the screw, it was one of two screws that attached the fork/swipe mechanism to the inside of the zoom, and reattached it. I replaced all the screws and electric cables to their proper places. However, I now get a Err 01 message on the camera! I’ve seen on your site, and others, that a faulty flat cable mechanism on the 17-88 lens can cause this message; but I’ve seen nothing about this on a 17-35mm lens. Could I have damaged the flat cable when I opened the lens? Will replacing it fix the error message?
    Any other ideas?

    • canonrepair says:

      Thanks 🙂

      By the Canon lens I have seen many cases, when even small faults (for ex. aperture problem) will cause illogical errors. For ex by the 17-55 F2,8 IS the aperture error makes problems by the AF function and the IS…
      So, it can be the flex cable, but can be for example the position sensor – the metal comb on one of the barrels.
      No other method – systhematic check.

  176. Lukács István says:

    Szia Gábor.
    Nem nincs hibakód.
    Van úgy hogy simán lehet vele éles képeket fotózni ,de vannak esetek hogy eggyáltalán nem tudja élesre beállítani.

  177. Lukács István says:

    Kedves János.
    Szeretném a tanácsodat kérni 2 problémával kapcsolatban.
    Vettem egy autófókusz hibás Canon EF-S 17-85 IS USM obit, kicseréltem a szalagkábelt, de sajnos nem szűnt meg a hiba.
    Lenne ötleted, hogy esetleg mi lehet a hiba oka (lehet USM motor hibája)?
    Van egy CanonEOS 550D-s gépem most, hogy próbálgatta a fenti obit azt vettem eszre, hogy ferde a keresőben látott kép (a szobában a szekrényt nézve vettem észre).
    A Kit obival is ezt csinálta.
    Szerinted mi lehet a hiba?
    Előre is köszönöm!

    • canonrepair says:


      sajnos a blendekábel forrasztása nem mindig sikerül, van, hogy nem éli túl a blendemodul – valószínűleg a végállásérzékelő optokapu halálozott el.
      Lehet hozzá rendlni teljes blendemodult. Vagy mégiscsak rosszul forrasztottál.
      Ettől még persze lehet hibás az USM motor is. Mi a pontos jelenség?

      Ha a keresőben ferde a kép, akkor ferdén áll a főtükör. Speciel pont az 550d-ben elég bénán oldották meg. Ezt ne próbáld otthon szétszedni, mert utána sokkal nehezebb lesz beállítani a CMOS-t. Olcsóbb, ha rögtön elhozod.

  178. Paveszka Sándor says:

    Kedves János!
    Tegnapi napon az alábbi üzenetet kaptam a hivatalos márkaszervíztől, a tisztításra otthagyott EOS 7D gépemmel kapcsolatban:
    A mattüveg karcos, a készüléket valószínűleg szétszedték, hiányoznak a csavarok. A gépben minden alkatrészen nedvességnyomok vannak, a CMOS filmsíkját elállították. A megbízható működéshez mindent cserélni kellene, azonban ez gazdaságtalan, ugyanis meghaladja a készülék újkori értékét.
    A mattüveg számomra a leglényegtelenebb dolog, de a többi információ kicsit aggaszt.
    Képet is kaptam mellékletben a fényképező belsejéről, azt esetleg el tudom küldeni, ha segít megmondani, hogy meg lehet-e javítani, vagy hogy érdemes-e.

    Előre is köszönöm a segítséget.

    Paveszka Sándor

    • canonrepair says:

      Kedves Sándor,
      a mattüveggel nem sokat lehet tenni, bár ha kosz is van rajta, azt nyilván el tudom távolítani.
      A cmos-t teljesen vissza tudom állítani az eredeti pozíciójába, időigényes művelet, de megoldható.
      A nedvességnyom attól függően kritikus, hogy mikor történt, meg hogy esővíz, csapvíz vagy tengervíz. Ez szétszedéskor látszik, meg az is, ha esetleg valóban korrodálódott is valami. Ha még nem, akkor az ÖSSZES panelt, kábelt ki kell szerelni, elmosni vízben, majd alkoholban stb, majd utána kiszárítani.
      Mindenképpen gyorsan, mert ha a teljes gép nem lenne megmenthető, még akkor is meg kell menteni minden használhatót.
      Természetesen érdemes vele foglalkozni.


      • Paveszka Sándor says:

        Kedves János!

        Nincs tudomásom róla, hogy a beázás mikor történt, az biztos, hogy több, mint fél éve. A fényképezőgép azóta is hibátlanul működik, de a hivatalos szervíz szerint nem gazdaságos a javítása. Igaz, én ezen alkatrészek javítását nem is kértem, egy szétszedéses szenzortisztításra küldtem be a fényképezőgépet.
        Esetleg a szenzor rossz elhelyezkedése milyen optikai hibát ad a képen? (Én személy szerint kicsit több, mint 5 éve fotózom, de semmi hibát nem tapasztalok a képen.) A visszahelyezését Ön milyen árért, milyen idő alatt tudja vállalni?
        Előre is köszönöm a válaszát.

        Paveszka Sándor

  179. Damir says:

    I have Canon 24-105 4L IS USM, with error 01 (Flex Cable i think)….
    I completly disassembled the lens, and then assembled it again (without any replacement of parts), and it worked again, just when I thurn the IS on, it starts to jump creazy from time to time…
    What could it be????

  180. Endre says:

    Kedves János!
    Van egy 30D-m, amin az exponálógomb valószínűleg elfáradt – a január 18-i bejegyzésedben leírtakhoz hasonlót produkál. Tudsz esetleg segíteni?
    Előre is köszönöm:

  181. aaf says:


    what the best temperature on soldering the flex on lens and also the best methode to do that 🙂 thanks in advance

    • canonrepair says:

      the best method is to use desoldering wire at first. for soldering I use a weller iron, I don’t know the exact temperature, but I think high temperature and short soldering is better then low temperature, because the plastic base could be melted.

  182. Simon says:

    Do you have a used or broken 350D main pcb? I would desolder some FETs as replacement.


    • canonrepair says:

      in fact yes, but I keep them for spareparts. What do You need exactly?

      • Simon says:

        I just ordered some replacement mosfets for the 1.2V circuit and the 14V. Its hard to get the original ones as they are no longer produced. But i think i found some replacement types. Unfortuantely in different packages but i should get it mounted.
        If that does not bring it back to live i think i would need a whole main pcb 😦
        But first i will give the replacement a try.

  183. Simon says:


    I hava a new toy/patient:a broken 350D. One problem was a broken shutter button
    (i soldered in one from a broken powershot camera, perfect fit & working).

    The only problem left is that the TFT does not work at all.
    The TFT backlight stays off and i can not see anything even when i put an external lamp next to it.
    The Background LED for the LCD does not work as well.

    The two fuses i found are ok. Any hints? Do you know where the voltages are generated? Th supposed DCDC Board (that is soldered to the battery compartment) does not look like that there are stepdown/up converters.
    To me it looks like the Stepdown/up converters are on the main PCB? Can you confirm this?
    The number of Inductors (6) matches the 6 voltages i can see in the part diagram.


    • canonrepair says:

      the backlight gets 14 volt from the dc-dc board, as I see on the wiring., and on the display panel should have only a switch (a fet i think).
      If You need, I have a used back panel (complete).

  184. Gergo Onodi says:

    Tisztelt János!
    Egy árajánlatot szeretnék kérni egy Eos 550D “takarítására” szeretném eladni, de nemrégiben észrevettem, hogy koszos a mattüveg, de a takarítás közben megkarcoltam. szerencsére semmit sem befolyásol, de szeretném ha szakértő kezek takarítanák ki a gépet, és amennyiben megoldható szeretnék árat egy mattüveg cserére is, amennyiben ez nem aránytalanul drága.

    • canonrepair says:

      Kedves Gergő,

      hát 550d mattüvegem az nincs, ha esetleg másig vázé jó bele, akkor ki lehet cserélni. A takarítás gondolom tükörakna, mattüveg plusz cmos nedves tisztítása lenne, ez így együtt kb 5000 forint ennél a kategóriájú gépnél (számlával).


  185. Tisztelt János!
    A következő baleset történt a tegnapi napon; Terepen a szántón, a térdig érő belvízes sárban elestem, és megmártottam a saras vízben a Canon 40D-met.
    Eleinte be sem kapcsolt, meg néha érthetetlen módon kattogtatta a zárat, de mostanra itthon sikerült úgy megtisztítani, szárítani, hogy minden funkciója, gombja működik.
    Azonban rátéve az egyik objektívemet, mikor lőni akartam, kiírta az ERR01-est, miszerint ha jól értelmeztem az elől lévő érintkezőivel lehet a probléma, ugyebár nem érzékeli az obit, nem tud fókuszálni, nem látja a rekeszt..
    Ez ha jól sejtem, mindenképpen a gépnek tudható be, mivel az összes objektívemmel megpróbáltam, és amelyeknek van autófókusza, azaz elektronikája, azokkal nem működik, csak a manuális obijaimmal.
    Mi lenne a teendő?
    Előre is köszönöm válaszát.
    Kőrös Tamás

  186. Berényi Zsolt says:

    Kedves János!
    Van egy Canon 50mm f1.8 lencsém ami “szétesett” (fókusz gyűrű és az objektív burkolatnál szétválik.
    Vállalja a javítást?

  187. abb says:

    Very good blog, I have two 40D and try to solve the errors that they have but I would not open them because I do not have experience.
    The first one is throwing Err 99 when try to shot, the problem I see is the curtain that does not open (ex. in live view everything is black, the senzor is not exposed). Is possible that the shutter is broken? Should I send it to service?
    The second has some problem now with the shutter button, the AF press stage is not working fast (I work now with AF-ON to lock the AF), the fire stage is working normal. Cleaning from inside out (where the battery is) with alcohol can damage the camera?

    • canonrepair says:

      If You get the ERR99 only after activating the shutter, and the shutter works, thats fine. (err 99 could be the mainboard too – thats much worst.) Yes, you have to send it to the service – or to me. (Post to Hungary is ca 24 EUR, back the same). About the repair cost we can discuss in mail. I have used but perfect shutter for ex, and I can adjust the body after repair. In some cases there is possible to adjust mecjanically the shutters springs too.
      About the second question: pls don’t do idiot things like cleaning a bad pushbutton with alcohol. A pushbutton has a lifetime, it should be changed. I can do it for You too – or the service.
      By a servicing normally You get a cmos cleaning too – which is not so bad for the camera.
      And You can write me in the mail in german language too.

  188. dorian says:

    Hi! I have a Canon 50D with a bit of history behind it: I broke off two pins of the CF socket last year, found a guy in Germany that went on to fix it. Got it back after a while, saw the guy had screwed up something on the main pcb and got a replacement one from ebay. Now the camera works fine except one thing: AF. In Liveview with that contrast-focus it works ok, but the usual phase-detection-AF sensors don’t work. When they say it’s focussed correctly it really is not. Now I’m thinking there’s two possibilities: either my good repairmain screwed up something else (I don’t know whether he tried to remove the wrong part and accidentally unscrewed the sensor or sth. like that) or the camera main pcb gets an initial focus calibration at the factory that it’s missing now. What do you think?

    • canonrepair says:

      Dorian, if You change the mainboard You HAVE TO reprogramme it for the body. Not only for the AF – there are a lot of specific values. You have no other chance, bring the camera to a workshop, which has the Canon software or the SPT software. I have the SPT but only for 40d.

  189. rp says:

    Szia János, az 5d2 vázam produkál olyan érdekes jelenséget, amit nem tudok hová tenni. Az optikai keresőben a kép időnként elsötétül fókuszálás után de még exponálás előtt. Ha kicsit föl-le döntöm a gépet, akkor elsötétül-kiváligosodik-elsötétül. Az obi levétele/felcsavarása és egy ki-bekapcsolás megoldja a problémát. Több objektívvel is csinálja, nagyon rendszertelenül. Van hogy hetekig semmi, aztán naponta 1-2x előjön. Van ötleted hogy mi lehet a probléma? Köszi és üdv r

    • canonrepair says:

      valahogy elmaradt a válasz – bár nem is tudom, mit írjak.
      ilyet ugyebár az okoz, ha a váz aktiválja a blendebeugrasztást.
      azt pedig egy kapcsoló (nyomógomb) tudja csak, ami a váz oldalán van, az optika mellett. Kontakthiba? Elszabadult csavar?
      Én megnézetném belülről valakivel.

  190. Alexandru says:

    Sorry but sent it to canon for repair end naw is not efficient to take it back for repair.Your price is good!thanx a lot!keep in touch!i repair cameras for my self end y have too spare parts.for naw i have a canon 10d for spares!if you ever need a part for that camera please ask!by the way you have a great blog!

  191. Alexandru says:

    Hello!what is the cost for the canon 40d dc/dc booard?thanx in advance!

    • canonrepair says:

      let we say 35 EUR.
      the problem is, that exactly by the 40d a part of the dc board is integrated on the flash board (the board on the lower side of the camera).
      Are You sure , that the problem is with the upper (DC-DC) board?
      I prefer to repair a camera by myself, it’s more secure for You too, and in that case I can check the 40d with the service software (for no suplementary charge), or to make fo example focus adjustment for some symbolic money.

  192. Mezei Zsolt says:

    Köszönöm! Idő közben azonban a blog leírásai alapján (! :)) ami hibátlan útmutatást nyújt , szétszedtem a gépet .A hátsó panel árnyékolók és a szalagkábelek láthatólag viztől rozsdafoltosak voltak !Weller pákával , (mivel a múltból még az is van ) árnyékolók le ! Kontakt sprével 95 % letisztítottam őket ! A gép nem működik – akksi ki ! Másnap reggel mivel a gépeknek lelkük van ugye ,még egy próba ! Hibátlanul minden funkció működik !!Ezután fotózás ,a képek mentése ,hibátlanul működik! – – Akksi ki ,megint teljes sötétség ! ! 2-3 óra akksi nélküli “pihentetés” után ,de ismét működik ! Lehet hogy az akksi -nál van kontakt hiba ,de a fémvázat már nem mertem szét bontani ,így azon a panelen nem tudtam megnézni a kontaktust. Még valami – a dátumot is nullázza ,ha a hibát produkálja , pedig első lépésben kicseréltem a 3v-os memória gombelemet egy újra ! Szeretném megmenteni a gépet , mert nekem megfelelő képeket készít . Várom a további véleményét , addig is egyre többet próbálom a gépet ! Köszönöm a figyelmét ! M. Zsolt .

    • canonrepair says:

      ez az a pont, ahol a panelokat kellene kicserélni, esetleg azt a kábelt lehet ellenőrizni, ami a kis gombelem feszültségét, viszi a főpanelra. Bár ha ilyenkor minden halott, lehet, hogy a testkábellel van a probléma, mert abból csak egy van mindkét áramforrás számára

      • Mezei Zsolt says:

        Köszönöm a választ ! A test kábelt majd megnézem ,de tényleg érdekes a dolog ,mivel két nap alatt a sok ki-be kapcsolás és akksi töltés után jelenleg a gép már tökéletesen működik.Most egyáltalán semmi hiba nem jelentkezik !!!Gondolom sokat segített rajta az Ön útmutatásai alapján elvégzett tisztítás is ! Ezért is köszönöm a sok segítséget amit Ön nyújt a fotósoknak a munkájával !! További minden jót kívánok . Mezei Zsolt .

  193. Mezei Zsolt says:

    Tisztelt Uram !Vettem egy rég nem használt “nem működő ” de két jó objektíves Canon 350D gépet kezdő tükör reflexes gépnek ,tárgy fotózáshoz..A gép évek óta nem üzemelt ! Reméltem csak akksi probléma.Vettem új 850 mAh-s akksit..Töltés után a gépen a kijelző kb 20-30 bekapcsolás közben 2 szer működni kezdett ,majd elsötétül, és a gép teljesen ” néma” .Kiváló blogját olvasva kontakt hibára gyanakszom .Tanácsát kérném abban ,hogy meg merjem bontani a gépet ,mivel 20 éve finom műszerészként dolgoztam , de az elektronikához mérés szinten nem értek ! Köszönettel :Mezei Zsolt

    • canonrepair says:

      Bocsánat, egyszerűen elfelejtettem rá válaszolni.
      Én nyilván azt mondom, hogy meg kell bontani a gépet, ahhoz csak egy PH00 csavarhúzó kell – ugyanakkor a hibakereséshez már szükség van némi elektronikai tudásra, finom pákára, multiméterre, esetleg donor alkatrészekre (mert azzal 5 perc alatt el lehet dönteni, hogy melyik fődarab hibás. Ez utóbbiak miatt tehát inkább nem bátorítanám.
      A problémák a hátfal levételénél kezdődnek, hogy ne szakítsa le egy mozdulattal a flexibilis kábelt.

  194. Gergo Onodi says:

    Kedves János!
    A egy olyan talán nem túl szokványos kérdésem lenne, hogy egy 550D-nek rázásra szabad-e lötyögő hangot adnia? Körülbelül a mattüveg magasságából hallom a hangot, mintha egy csavar, vagy müanyag pöcök elszabadult volna. Valamint sokat próbálgattam, és gondolkodtam, hogy esetleg a vázam valamilyen módon fókuszhibás, mivel egy időszakban az elkészült képek jórésze fókuszhibásan jött vissza gépre töltéskor (olyan minimális hiba hogy az lcd-n nem látszott) de később elvetettem ezt az elméletet mivel azokat a képeket főleg újrakomponálással készítettem nagy fényerejű objektívekkel.
    Tudna esetleg árajánlatot küldeni a zörgő alkatrész kivizsgálására, és egy fókusz ellenőrzésre az objektíveimmel? Üdv, Gergő

    • canonrepair says:

      a beépített vakus Canon-okban a vaku alkatrészei (kis fém összekötők). Ha kinyitod a vakut és megfogod őket, akkor ne zörögnek.
      Ettől még a gépben lehet egyéb elszabadult alkatrész.
      Ami a fókuszhibát illeti, eddig 2 550d-vel találkoztam, aminél ez jeletkezett. Nekem úgy tűnik, gyárilag rosszul tervezték meg a tükör felfüggesztését. lehet rajta módosítani – előtte persze tesztelni kell. Csak a teszt 2-3000 forint. Ha szét kell szedni és módosítani, akkor az nagyságrendileg 10-15000 forint (számlával) – szét kell szedni a teljes gépet.
      üdv. János

  195. aaf says:

    hello again,

    how to do to simple test to know the USM or mother board is defect? thanks…

  196. Tisztelt János,
    egy kiadós szánkózas utan a gépem nem ismerte fel tobbet az aksiját, vagyis nem kommunikáll vele… a gép amúgy müködik, viszont standby ban is lemerül…. Egy EOS 7Dről van szó, esetleg tapasztalltál hasonló problémát ? Talán a kondenz zárlatolt össze valamit? Köszönettel, Aba

    • canonrepair says:

      rákerestem, a net tele van vele, pl itt:
      viszont ez az érdekes:
      “Canon EOS 7D “Cannot communicate with battery” error
      The Canon 7D is an excellent camera and a true work horse. However, this camera is known to have problems which show up as an Error 30, 40 or 80. Since we specialize in camera repair, we see all sorts of problems. Recently, we received a 7D for repair, which was giving the “Cannot communicate with battery” error. Since we have the ability to plug the camera into the computer and download the cameras self diagnostics, we were able to pinpoint the problems, which were: the camera would not recognize the battery and would intermittently lock up, the self cleaning sensor function was also failing, all pointed to a problem with the lower PCB (printed circuit board). Now that we have identified the location of the problems, our lead repair technician Dave, disassembled the camera and found the following issues: loose ground screws and connectors going to the lower board, and the main flex connector between the lower PCB and main board had corrosion/tarnish on two of the points. After he cleaned all the switches, contact points, re-sealed the screws so they wouldn’t back out we re-programed the camera shutter through the specialized software the camera works flawlessly. In this situation, the cost to disassemble the camera completely, clean, adjust and reprogram the camera runs $249 in labor, which includes a 1-year warranty.”

      Attention! This whas only a quotation froma a site – I don’t know, if it’s true or not. (canonrepair)

  197. Simon says:


    My 50d works again, the motor was faulty although the coil, magnet etc looked good! strange!

    I have a new toy, a broken 50 f/1.4 lens. The AF USM motor does not move, it makes only a very slight noise.
    I took pictures with a scope from the signals (at the motor contacts).

    without motor connected i see some strange sine waves:

    when i connect the motor i see this:

    looks like the motor has a short circuit?! has anybody seen that before?

    motor dead or broken pcb?


    • canonrepair says:

      At the moment I have no oscillogramm, I will try to make it tomorrow.

      • Simon says:


        The lens is working again. I transplanted an USM motor from another lens repair part into that one. Works fine again!
        The broken motor has short circuits betwen 3 pins. No idea how that can happen.


  198. Dirk says:

    Hello, good forum here! i have a problem with a 40D which is completetly dead.
    Can you share with me where all the fuses are located on the camera (SMD fuses).

    • canonrepair says:


      as I know, the 40d has only one “P” type fuse (3 Ampere), it is located on the flash/dc/DC board, which is on the bottom. You can check this fuse only after taking out the board, because it is on it’s upper side. (A “P” is written on it).
      I have seen many 40d-s with small tin balls on the surface of the board – from the factory! This small balls can start to move on the PCB, making short-circuit between the pins. Check the surface of the DC/DC board too! (Located on the upper side of the camera).

      And if You want to sell the camera as it is, plese send me a mail.


  199. aaf says:


    nice blog and very good research….

    I have and already fixed aperture cable of TAMRON 10-24 the problem is if take photo with camera mode I got the error report but if take in video mode the photo is fine (I also test the aperture lens in video mode and the diapraghm is fine from the biggest to smallest opening) so the problem seems not in diapraghm.

    whats the problems of this symptoms, any suggest? thanks

  200. Farkas Szabolcs says:

    Kedves János!

    Még augusztusban vettem egy használt Canon 1D mark II gépet, ami valami okból kifolyólag, ha túl világos háttérrel fényképezek valamit, mindig túlexponál, sötét képet csinál, teljesen sötétet. Nem is kell exponálni, már a fénymérésnél nagy zársebességet javasol. Ha a kompenzációt +3-ra állítom, akkor csinál jó képeket. Az az érdekes, hogy sötétebb háttérben, pl. erdőben, teljesen normál képeket csinál a gép…

    Ön szerint mi lehet a hiba?

    Segítségét előre is köszönöm, üdvözlettel:


    • canonrepair says:

      arra tudok gondolni, hogy esetleg valamilyen belső fényelnyelő felület levált / hiányzik, ezért a világosabb kép betükröződik, és több fény kerül a fénymérőre, mint kellene. gondoltam még nem bele való mattüvege is, de +3 fényérték az rengeteg.

  201. bertus11 says:

    Canon EOS 40D
    I have a problem with a Canon 40D.
    When I switch on power I get an error message that the CF card is not formatted.
    When I go in the menu to “Formatting”, after a few seconds with a status bar
    filling to the end, it ends up with the message “cannot format the CF card”.
    I have the same problem wit a card that comes right out of a camera that stored
    foto’s on this card, so it cannot be a formatting problem.
    I looked to the pins of the slot but no pins look to be bend.
    I’m affraid that there is a hardware problem in the camera and as far as I can
    see, the CF-slot is on the main PCB.
    Does this mean that the main PCB is broken or do you have an other idea?


    • canonrepair says:

      It can be a blown fuse.
      The CF card driver is on the main board…..

      • bertus11 says:

        I got an other 40D today. I put de mainboard of the camera with the CF error in the new camera and got the same problem in the new camera, so it seems to be a problem with the mainboard. I looked for fuses on the mainboard but could not find any fuses. Do you know if there are fuses on the mainboard or are they perhaps on the DC/DC board?

      • canonrepair says:

        bottom board (with the big capacitor).
        DC board? (not sure)

  202. Szia János!
    Kaptam egy canon 350d használt gépet. A gépnek egy hibája van, néha error 99-et csinál.
    Több dolgot kipróbáltam már, hogy hátha megszűnik, de sajnos nem jött össze. Most sikerült kipróbálnom másik obival is a gépet, és így már nem csinálta. A géphez gyári obit kaptam canon zoom lens ef-s 18-55mm. Utána olvasva, azt a hibát kaptam, hogy ezeknél az obiknál az átvezető kábel sérül, és ez okozza az error99-et. Legtöbbször akkor kapom a hibát, ha nem közelíttek rá az obival semmire, ha közelíttek, akkor többnyire jó képeket csinál. Kérdésem az lenne, hogy házilag ki lehet-e cserélni a kábelt, illetve hol tudok ilyet beszerezni?
    Előre is köszönöm.
    Üdv: Isti

    • canonrepair says:

      ez most 18-55, vagy 18-55 IS?
      Utóbbiban a fókuszvisszajlező kábel szokott eltörni (ha leveszed a bajonettet, már látszik), előbbiben a blendekábel.
      A fókuszvisszajelző a “focus flex cable” varázsszavakkal kereshető meg az ebay-en, a másik pdig “aperture flex cable”
      Természetesen mindkettő javítható otthon.

      ui: a bajonettet csak óvatoan, mert az IS-nél arra megy egy vékony flex-kábel!!!

      • isti624 says:

        Ez a 18-55-ös optika. Tehát akkor nekem a “aperture flex cable” kell vennem.
        Ez egy általános kábel, vagy obiként változik? pl.18-55-be ugyan az van mint a 18-85-be?
        Érdemes javítani, vagy vegyek egy használt,de még jó obit? (ugyan ilyet)
        Még egy kérdés: Ha vennék egy új obit akkor te milyet ajánlanál nekem.
        Tudom attól függ, hogy mire használnám. Átlag felhasználás lenne. Családi fotózások, kert, virágok stb. Nincs más obim hozzá.
        Én ezt néztem ki :Canon EF-S 18-135mm f/3.5-5.6 IS
        Előre is köszönöm szépen.
        üdv: isti624

      • canonrepair says:

        Akkor sorjában.
        Azt, hogy melyik kábel halt meg, akkor tudod biztosan,, ha szétszedted. nem olyan bonyolult, de kell egy VÉKONY PH00 csavarhúzó. Ha a bajonett lejött, a többi már általában látszik.

        Ha kevés a pénzed, akkor én mindenképpen egy canon EF-S 18-55 IS optikát vennék (kb 18-20000) (egy felújított, kábelcsere utáni nekem is van eladó), meg egy 50 mm F1,8 optikát (ez utóbbit újat, 30000 ft. az 50 mm ezen a gépen kiváló pl portréhoz és kifogástalan a képe)
        Ha asok a pnzed, akkor EF-S 17-55 F2,8 IS. Ez nagyon jó, de használtan 160-180000 forint.
        Olyan optikát, aminek az átfedése több, mint 4x, nemigen vennék meg.
        Vehetsz még 17-85 IS-öt is (használtan 60000) – kicsit torzít a képe, de annak nagyobb az átfedése. Ha eltörik a szalagkábele, akkor persze szívás.

  203. Simon says:

    Just by chance: Do you have a 40d/50d mirror motor on hand where you could measure the resistance?
    I measure between 6.4 and 10 Ohm for the mirror motor (depending on the Temperature).
    The curtain motor measures 3.6Ohm.


  204. Simon says:

    Some more discoveries – still no idea what goes wrong.

    I measured the position encoder signals, in the case of the described error
    i can see that the encoder is rotated further than it should.
    (i opened the sensor, everything fine)

    Watching the motor voltage i can see a waveform like
    |““`|_|`|_____ = error
    |““`|__________ = no error
    the signals going to the motor driver seem to be always like this:

    So either the motor driver ic is faulty or something strange is going on.

    Interestingly i think i located the position where heat toggles the problem:
    If i warm up the motor for the mirror the problem apears – if i cool it down with ice spray the symtoms go away.
    It could make sense that a warmer motor will move more easyly with the second strange pulse – causing the issue.

    Any hints?

    I think i will swap the motor for the curtain and the mirror to see how it goes then.
    Another option would be replacing the motor driver ic (i do want to buy a new bottom pcb).


  205. bertus11 says:

    Canon EOS 40D
    I have a problem with a Canon 40D.
    When I switch on power I get an error message that the CF card is not formatted.
    When I go in the menu to “Formatting”, after a few seconds with a status bar
    filling to the end, it ends up with the message “cannot format the CF card”.
    I have the same problem wit a card that comes right out of a camera that stored
    foto’s on this card, so it cannot be a formatting problem.
    I looked to the pins of the slot but no pins look to be bend.
    I’m affraid that there is a hardware problem in the camera and as far as I can
    see, the CF-slot is on the main PCB.
    Does this mean that the main PCB is broken or do you have an other idea?


  206. Simon says:

    Ok thanks for the info. I gained some more clues. When i heat up the left side with the digic cpu a lot after some time i get the symtoms.
    It is interesting, when the heat bug occures any button press (also changing af to m on the lens) will force the mirror to go up.
    So i do not think it is a contact/sensor problem. Maybe a bad capacitor and a voltage drop?!

    I will get some ice spray to define it further (i can not heat single parts selective enough, so i will go for a warm up and selective cooling approach ;))


  207. simon says:

    Interesting concept!
    I Made a mistake, i meant the Motor for the mirror.
    How does this One work?

    Regards Simon

    • canonrepair says:

      As I know, this second motor rotates also in only one sense.
      But each eos camera has some “H” bridge driver IC-s, and if they get only one fautlty bit, they start to go strange

  208. Simon says:


    Do you know how the shutter mechanism works?
    Does the motor move back and forth (2 directions) or is it solved mechanically and the motor is always rotating in the same direction?


    • canonrepair says:

      only one direction.
      the motor drives a wheel with a cam. the phase sensor tells the exact position, and the motor stops in the correct moment.
      when battery connected, the curtains are always in “armed” position, so with te tensioned spring, but exactly before moving – this is made by the internal structure of the shutter (to have a short time lapse). when presseing the button, the motor has to move only a little to engage the movement of the curtains – which in that moment are already holded by the solenoids.
      Therefore exact startpoint will be determined by the two solenoids.

  209. Simon says:


    Now i have more information. The owner gave me incorrect information.
    Yesterday i was finally able to reproduce the error.

    If the cam is cold, everything is fine.

    I warmed up the internals using a hair dryer – still fine.
    Then, some minutes later out of a sudden the problem appeared:
    The mirror goes up (you can see the curtain). Pressing a random (?) button makes the mirror move down and up again.
    Usually it stays at the top. Removing the Lens also lets the mirror do a noise/movement (?).

    My next take will be a seperated warming up of the single pcbs and/or maybe pcb regions (cpu etc).

    At work i develop electronics so i have the skills to try the repair on my own 😉
    I sucessfully repaired other canon stuff in the past (several ixus, lenses, 40d).


  210. simon says:

    Canon eos 50d

    I have a broken 50d with the following symptom: after long use the camera shutter goes into an endless loop. have. you seen that before? any hints?

    • canonrepair says:

      Hi Simon,

      the Canon EOS cameras usually have a basic function: if You connect the battery, they try to find the zero position with the motor (even by turned off camera!). The position is given by the phase-sensor. The motor is driven by a PCB which works even without the main PCB.
      If the phase sensor, or the motor PCB is bad, or gets wrong information, the motor strats to rotate the mechanisms endless. In this case the two solenoids will get no current, so the curtains will go up and down. It can be cause also by a blown fuse (depends from the body).
      You have to disassemble the body, check the fuses, check the phase sensor, and the flex cables. If you are not used to do such things, better go to a specialist. Where do You live?


  211. Makai Sándor says:

    Egy apró információt szeretnék tőled kérni. Van egy 550D vázam, és már többször vittem be a garanciális ideje alatt a Kamera Kft-hez, mert szerintem front fókuszos, de egyszerűen vagy képtelenek beállítani, vagy nem törödnek vele, hátha megunom, hogy 2 hétre mindig ott hagyom a vázat. Kérdésem, hogy te vállalsz-e és ha igen mennyiért egy autó fókusz beállítást. Megjegyzem, LiveView módban tökéletes a fókusz.

    • canonrepair says:

      Azóta már találkoztunk, a mérés eredménye az volt, hogy az én (jónak ismert) 50 F1,4 optikámmal gyakorlatilag tökletesen fókuszolt a gép.
      Tény viszont, hogy a fő tükör sarkait tartó kengyelnek, (és ezáltal a sarkoknak is) elég komoly játéka van már kis nyomásra is. Tapasztalatom szerint van olyan gép, ami erre a fókusz időnkénti tévesztésével reagál.
      A LiveView nyilván tökéletes képet ad – hiszen ott arra állítod az élességet, amit a CMOS lát.

  212. Farkas Szabolcs says:


    Egy Canon 20d-vel használok egy Canon 400mm 5.6-os objektívet. Sajnos nem igazán sikerül tökéletes éles képet készítenem a kittel még a legnagyobb blendével jó megvilágításban sem. A gép vagy az objektív lehet a problémás? Lehetséges, hogy kalibrálni kellene az objektívet? Ez utóbbi még garanciás…



    • canonrepair says:

      Kedves Szabolcs,
      persze lehet éppenséggel, hogy az optika hibás, azt mondanám, előbb ki kellene próbálni egy garantáltan jó vázon. ha csak annyi a baja, hogy front/backfókuszos, akkor azt nyugodtan okozhatja egy elállítódott autofókusz a 20d-n. Ha viszont valóban nem lehet vele éles képet készíteni,a akkor persze marad az optika ellenőriztetése. Ez utóbbi – ha még garanciális – végül is ingyen van. Szóval előbb teszt másik vázzal – célszerűen egy live-view-val működőt választanék, mert ott a képérzékelőn kialakult legjobb (legélesebb) állásban lehet exponálni. Ha az is rossz – na akkor biztosan az optika a hibás. Nem esett le? Mármint az optika.

  213. Zöldi Péter says:

    Szia 🙂
    Segítségedet kérném 🙂
    Most cseréltem egy panasonic LS 80-at egy canon 300D-re
    az objektív teljesen hibátlan 🙂 a géppel elvileg annyi gond van hogy nem müködik a kis fekete fehér kijelző felül (akivel cseréltem az donor gépnek vette de végül nem lett semmi kieszdve belőle mert átpártolt nikonékhoz) , és ha jól láttam a memóriakártya foglalatól egy darab kis pöcök kivan törve
    hazafele fotoztam vele de ugye nem tudtam állítani semmit rajta de már nem tudok vele fotozni mert csipog és villog . ez mitől van? és a fent említett dolgoknak mennyi lenne a javítása kb?:)

    Üdv: Péter

    • canonrepair says:

      írtam mailt.
      a kijelző lehet szalagkábel-hiba is.
      a CF kártya lába általában nem gond, mert általában a plusz vagy test törik ki, amiből 2-2 van – csak ne a vázban kóboroljon.

  214. Emődi Csaba says:


    Van egy Canon EOS 350D masinám. Egyszer a képek letöltése közben véletlen lehuztam az USB-t, és azóta amikor bekapcsolom csak villog hogy Busy. Semmire nem reagál.

    Milyen megoldást látsz a problémára?

    Üdv. Csabi.

    • canonrepair says:

      hát nincs túl jó hírem. Sajnos elképzelhető, hogy a főpanel halt meg benne, akkor pedig nem tudok megoldást, mert nem nagyon van donor. Egyébként meg persze szét lehet szedni, megnézni azt a néhány biztosítékot és reménykedni.

      • Emődi Csaba says:


        Némi update. 🙂 Ha bekapcsolás folyamán nyomva tartom az expo gombot, akkor készít fényképeket, de ha elengedem megáll. Ugyanezt produkálja mindenhol máshol. Pl.: Belépek a menübe, de csak lefelé enged lépni, nem tudok semmit változtatni, vagy amikor kiveszem az akksikat, akkor első indításnál rákérdez az időre, de ott is csak lefele tudok menni. Semmi másra nem reagál. Ez is lehet biztosíték? Ha “csak” bizti akkor van DIY módszer? Esetleg ránéznél?

        Üdv. Csabi.

  215. bertus_b says:

    Hello, I have some more info about my Canon 28-135mm.
    When investigating further I discovered that a flexcable from the focus position coder(inside the USM-unit) was damaged by the wobbling inner lens construction. This was caused by loosened screws. So you think this damaged flex prevents the correct focussing and not a defective main circuit board.

    • canonrepair says:

      it is not so easy to damage a main board.
      try to change the flex. if there is no flex for it, try with some thin wires – if there are only a few wires in the flex.

      • bertus_b says:

        I ordered a new USM motor and replaced it. The lens is working perfectly now.
        Delivery of the USM motor took several month, so it took a long time to end this thread.

  216. bertus11 says:

    Hello, I have a question about a canon 28-135mm.
    The autofocus works just in one direction, so it looks as if the USM-motor only turns one direction.
    If I focus to a close subject manual and go to a distant subject in autofocus the focusmotor works but
    gives an oveshoot and doesn’t correct back.
    If I focus to a distant subject manual and go to a close subject in autofocus the focusmotor doesn’t seem to react.
    I replaced the USM-motor by an USM-motor of a Canon 17-85 (looks quite similar) but I got the same results. I think the electonic board is defective. What do you think?

    • canonrepair says:

      the USM motor itself does not know, how much to go in a direction. It always should be there a position sensor. The 17-85 has 2 pieces. One is for absolut position – a flatcable with coding sectors and a comb, which reads the position (on 5 bits for ex.). This is a bad resolution (32 positions) – but gives the absolut focusing position. The other one is a relative sensor, an optical encoder, which gives very precisely the movement – but only steps (and probably the direction). Both of them could be damaged, and can cause a malfunction of the focusing.
      The encoder You can only wipe with some alcohol, the other one You can wipe too, and I had a case, when the solution was increasing the pressing force of the comb (only slightly!)

      • bertus11 says:

        I ordered a new USM focus motor and hope that this will fix the problem.
        I will keep you informed.

      • canonrepair says:

        OK, be careful by the assembling.

      • bertus_b says:

        I have a problem with 2 lenses of the type 17-85mm where I think the problem has to do with the USM motor. Both lenses had problems with the diaphragm. After the diaphragms where replaced the lenses seem to work again, but… one of the lenses starts hunting when focussing on a close subject (e.a. 60cm). The other lens starts hunting when focussing on a subject at definite distance. I thought it could be a problem with the position coding of the USM motor. What do you think how I can solve this problems.

      • canonrepair says:

        the USM motor has always two position sensors: on absolute sensor, which is a brush on a flex cable with some lanes, and an incremental optical sensor. Both of them can be damaged or can have a bad relative position. Try to fix this.

        Ruzsa Janos

      • canonrepair says:

        check the position and contact of the brush check the optical ring to be clean

        Ruzsa Janos

  217. szule says:

    Kedves János,
    Adott egy 30D, ami aksi behelyezéskor azt produkálja, hogy a print/share gomb kéken világít, és semmi más életjelet nem ad. Az előző tulaj szerint 99-es hibával kezdődött a dolog, de mire nálam kötött ki a gép, már csak a kék fény világított. Külömböző fórumokon azt az infót találtam, hogy a DC board cseréjével megoldódik a dolog. Feltételezem, hogy itt nem csak a biztosítékkal van gond. Van-e rá esély, hogy javítható a DC áramkör?
    Nagy M. Zoltán

  218. tiszafoto says:

    Kedves János!

    Elestem a gépemen egy Canon Speedlite EX II vakuval. A vaku a földhöz verődve szabályosan letört a gépről. A törés maga a műanyag vázat érinti a vaku alsó részén, a talp fölött. Minden más érintetlennek tűnik, a vaku működik. Kérdésem, hogy a műanyag váz cserélhető-e egyáltalán, vagy valamilyen módon rendbe lehet-e hozni. Kár lenne érte…
    Fényképet is tudok küldeni (de nem találtam e-mailcímet az oldalon).

    Szabó Tibor

  219. Djordje Markovic says:

    Good Morning,

    I have a question about Canon EF-D 17-85 USM IS ultrasonic lense.

    Well I had a problem with blocked zoom, and i solved it (zoom guide screw to srew again) and since i