DIGITAL CANON repair blog

USM refurbishing

Posted on 2020. November 29. by canonrepair

Cleaning of the optical encoder ring helps only the focus hunting cases.
When the problem is with the usm ring, I refurbish them with degreasing, polishing both rings to get back the plane, shiny surfaces, then cleaning again, after which mounting together.
When mounted, you have to try to rotate the plastic/metal ring relative to the metal one. IT MUST have a high frequency sound. Case not, just rotate them, till you get that annoying noice. This brings together the surfaces very close, so they adhere to each other – and USM starts working.
Here you see my small polishing tool, made of an old HDD disk, which is the best plane, which you can get, and a battery screwdriver. Use some alcohol for moistening! Polishing paper: 2000.

Posted in General topics | 4 Comments

Eastern Egg in a 17-85 IS

Posted on 2020. November 7. by canonrepair

I had to replace the aperture cable – and I found the former one too, which the other service did not removed before mounting the new one.

They dont like to disolder?!

Posted in General topics | Tagged flex cable | 2 Comments

70d rotating LCD + 80D donor

Posted on 2020. September 6. by canonrepair

I had to repair a faulty shutter in a 70d. (on the photo there is a mistake. It is a comparison between 40D and 70D curtain).

As I did not have a new one, I searched for a good curtain from anything else around…. and the curtain from a good, practically new 40d does fit perfetly!

Problem solved, mounting together, works fine…. excepting the LCD, which has a contact problem. In fact the camera has been disassembled before 2 times by somebody else… Never pull them by the wires.

I always HATED this rotatable LCD-s They have to last +1 day aftr warranty expires, and as I could find replacement on ebay… Not me is the first, who needs this part. 🙂

But is in China, and even using that I should solder back 2 tiny wires.

So, I searched in my scrapheap… and I have found an 80d, which has the same cable!…. but not exactly.

The two microswitches, which give the position information of the screen, are not there in the 80d frame. Shit.

This switches put the 2 wires on GND case they are activated.

So, I decided to put two extra wires between the main board and the LCD frame, and the GND (minus) wire from the LCD board (as there was no space for 3 wires in the frames hole).

And…. works!

Here is the GND wire.

By the way: the tiny wires in the flex cable are SHIELDED (!!!) wires.

Posted in General topics | Tagged 70d, 80D, rotating LCD | 3 Comments

Damaged screw

Posted on 2020. June 1. by canonrepair

Case You have to screw out a bolt with damaged head (after forcing a stucked screw with the screwdriver can happen to damage the PH00 slot), You have 2 possibilities: to cut a simple straight slot with a small grinding machine (little bit dangerous, but sometimes is the only possibility), or to grab the head with a side-cutter, strong enough, that the blade enteres in the screwhead, and rotate it.

Posted in General topics | 1 Comment

Soldering irons: Weller and Fahrenheit

Posted on 2020. May 17. by canonrepair

I need at least 2 soldering irons: a “normal size” for everyday use, and a tiny one, with the tip like a needle.

A good Weller station is a lot of money, so i decided to use a Fahrenheit 28011 station. It is a chinese, khmmm, …. thing.

They offer many sizes of tips at a reosanable price – but sometimes i need the tiny Weller tip too, which is not compatible.

Or, better to say, was not, till yet.

Here can you see the difference. I tried to cut the end of the chinese, to mount there the weller tip – unfortunately the bore at the end of the tube is bigger.

So, as the Weller tube is a little bit thicker, i put it on the chinese tube, i soldered it with brass (hard soldering), i cut the ending of an original chinese tip – and now i have an upgrade kit for weller tips.

The other ideea was to solder with brass the tip on the other cutted tip.

Works too!

Yes, it is not too esthetic. And?

Posted in General topics | 7 Comments

SD-card – not working

Posted on 2020. May 13. by canonrepair

Case You have a 500d (or any other camera, using a SD-slot), can happen, that the camera does not feel the inserted card, or gets the false information, that the card is write-protected.

The cause is in most of the cases, that the two small switches, one for carde presence, and the other for write protection are damaged. To replace a card slot ONLY for this reason is dangerous for the board and a lot of work. Normally i rather make a bridge on the switch – a small wire and 2 solderings.

Her you see how it looks for the 500d. Just check the right soldering pafs on the PCB.

Posted in General topics | 1 Comment

Not starting DSLR – and the shorted motor

Posted on 2020. April 26. by canonrepair

I had to repair an old 40d (but in this case could be ANY other Canon DSLR), which did not start at all. No message on the displays, nothing. After inserting the battery there was a very tiny “tick” noice from the inside, but nothing else. I checked the following (by replacement of the parts):

– dc-dc board

– flash board with the single “P” type fuse (was ok, not burned)

– main board.

No change.

I tried to start WITHOUT the motors – and it started !!! But error code 99 on the display.

I measured the resistance of the motors: 3,3 ohm – which was the same for a known good one too.

I tried with an another, external motor: worked! (with error code, of course, as the mechanism was moving on the other camera)

I mounted a used, but known good motor into the board: worked!

I assembled a small testing circuit with a motor and a current limited source. Result: the bad motor draws more, than 1000 mA (with rotating of the rotor), the replacement only 65 mA.

So – the motor has an internal SHORT!

Now the camera workes fine!

The motor has an interesting internal construction: the stator is formed of a ferromagnetic metal tube and a cilindrical shaped coaxial (strong) magnet, the rotor is made ONLY of the copperwire coil, plus the commutator.

Posted in General topics | 2 Comments

No ideea what is wrong – search for the screws

Posted on 2020. January 5. by canonrepair

As You know, there are some cameras with typical falling out screws, which can make problems (7d, 5dI, 40d…).

I had to repair a 17-85 IS – always the same, aperture flex broken, and as a second mandatory thing, cleaning the USM (after complete disassembly).

This lens had a second problem: no zooming possible. After disassebly I have seen, that the metal lever is not on his place, the two small screws disappeared.

I repaired it, outgoing ckeck – IS not working, and making a rattling noice.

Hrrrrr.

Disassembly – no cable is broken.

Assembly. Rattling noice.

….

What else could be? And then i came on an ideea: what about the scres?

I disassembled again – and exactly on a coil of the IS, closed to the magnet there was one of the screws.

Assembly. Works!

Excepting the fact, that i have IS only on the vertical direction. I suppose, the screw distroyd somehow the windings on the coil.

I told to the customer, we decided to let it in this for.

So, NEVER give up, when searching for missing screws.

Posted in General topics | 2 Comments

AF sensor feedback LED dislocated

Posted on 2019. June 28. by canonrepair

During my ten years of repairing I have seen several times cameras with dislocated AF point LED-s. The symptom: you can see only a very dimmed red light or nothing at all.

In some cases the problem is the dislocated screen with the engraved squares – but sometimes the problem appeared after the owner dropped the camera.

The AF point LED-s are fitted on a small PCB, which is mounted on the top of the pentaprism. Between the LED panel and the pentaprism there is a small optical system, with a lens and moe prisms, which have the rule to project the image of the 9 (or any other number) of red points on the surface of the screen matte. The whole LED atrix is about 5×3 mm, you can imagine, what does it mean to put is back to it’s original position, and to glue it back.

And there is another problem: the LEDs make light only when the camera is assembled, and you press the AF points button. But in that moment you have no access to the LED panel to move it…

This camera today is an old 5d Mk1 – so nobody will pay for this operation – but the PLEASURE to do it….

I decided to make a small supply for the panel, I used a LiPo cell, approx 4,2 volts. I measured the LEDs pinout.

After finding the right polarity (common anode, so each particular LED gets the GND), I found the right two pins for the CENTRAL and one side LED. I needed two because the cetral position is the ost important, but I had to know the angular position too.

Next question: how much current?

You know, in the hungarian tales the dragon have always 7 heads. And do you know why EXACTLY seven? because 6 is a too small number, 8 would be too much, so, it is 7.

I was thinking that normally a small led takes 5-10 mA. This is a very small one, let give him 0,5 mA. As the lED-s opening voltage is about 1,7 V, from the 4,2 volt remains 2,5 V. I had there a resistor of 3,3kOhm, this makes a current of ca 0,75 mA. Little bit more.

And here it is:

Now I mounted it on it’s place, looked through the viewfinder…

After a 5 minutes of moving and positioning it was right on it’s place. Now I took some cyanacrilate glue to keep it in the right position (normally I don’t use it in cameras, as the produce a remaining white precipitation on the surfaces), .

After the glue hardened, I checked the LED-s position again, and I glued it with a 2 component glue.

And now: waiting. Exactly to write this post….

I have to put back the cable, and to check the lights.

Too much work for a 5dMk1. probably. But could be a more expensive camera.

Posted in General topics | 2 Comments

Canon EOS camera error codes and messages

Posted on 2019. March 23. by canonrepair

original here: https://cpn.canon-europe.com/content/education/infobank/camera_settings/eos_error_codes_and_messages.do

And here is a copy from the official Canon site, case you don’t find the original.

Camera settings: EOS Error codes and messages

When using your EOS camera you may occasionally get an error code or message appearing on the camera’s LCD screen. Most of these errors can be quickly and easily resolved – the various EOS error codes and messages are described below with information that should assist you in resolving your issue.

EOS Error codes

Err 01

Description: The communication between the camera and lens is faulty.

Resolution: Very gently clean the electrical contacts (highlighted in red) on the camera and the lens using a clean and dry cloth.

CAUTION

When cleaning the contacts take the following precautions:

Do not wipe the contacts with a wet cloth.
Do not touch the contacts directly with your hands. Touching them with your hands could cause corrosion, which would cause the camera to become inoperable.
When cleaning the contacts on the lens side, be careful not to damage the lens surface.

Err 02

Description: The camera cannot access the memory card.

Resolution:

Remove and re-install the memory card.
Format the memory card as described in the user manual. The user manual for your EOS camera can be downloaded by clicking here for the Canon Europe EOS camera support page.
If formatting the memory card does not resolve the error please replace the memory card.

Err 03

Description: There are too many folders on the memory card.

Resolution: Replace the memory card with a formatted Compact Flash memory card.

Err 04

Description: Images cannot be saved because the memory card is full.

Resolution:

Erase any unnecessary images on the memory card.
Format the memory card as described in the user manual. The user manual for your EOS camera can be downloaded by clicking here for the Canon Europe EOS camera support page.
If formatting the memory card does not resolve the error please replace the memory card.

Err 05

Description: The built-in flash could not be raised.

Resolution: Turn the power switch off and then on again.

Err 06

Description: The sensor cleaning is not possible.

Resolution: Turn the power switch off and then on again.