EF-S 17-85 IS – aperture change – as simple as possible – blende cseréje egyszerűen

The first disassembling of an unknown lens normally takes a lot of time for me – and sometimes I make unnecessary steps.

If You want only to change the aperture module, or only the aperture flat cable, You can do it in the following way (the first steps are not on the pictures, so the USM module and the electronic board are already dismantled.)
If You want to clean the internal side of the lens, You have to disassemle the lens completely, of course.


These are the 3 guiding rollers (in fact, there are 3 x 3 rollers, positioned at 120 degrees).
No. 1. is for the last lens group,
No. 2. is for the IS module moving lens,
No. 3. is for the aperture module.

IMG_5132 b

At first, You have to get out the No. 1. and 2. (3 + 3 rollers and 3 + 3 screws). At the first time is not very easy, because they sit very tight in their place. You can help this with a small flat screwdriver, or with a big wood-screw, using it like a cork-screw.   The best is, if You make a small tool for this operation, like this:


See here: https://canonrepair.wordpress.com/2013/03/16/lens-disassembling-tools-roller-extractor-clamp/

The rollers are apperently the same size, but is good to keep them separately for each group.

IMG_5134 a

Now You can pull out the last lens TOGETHER with the IS module (because the IS is in the inside of the lens module).

IMG_5136 a  IMG_5138

Don’t forget , You will have to put it back in this position. It’s easy because the two flat cables give you only one possibility.


IMG_5142 a

The next step: to take out the 3 rollers No. 3 (for the aperture module.)

IMG_5140  IMG_5141

You may take out the screw for the flat cable only now.

After that, you can pull out the aperture module, with the cable, and the long black metallic guide.

IMG_5148 a

Be careful, the new aperture comes without the metallic guide, so you have to use the original!

IMG_5143  IMG_5146


Assembling in reversed order 🙂

For greasing the guides, rollers I used a PTFE + silicone oil based grease – (in fact a grease for Volvo cars), but be carefull, only the really needed amunt, otherwise You will have grease on the lens.

By the last lens which I’ve repaired I tried to change only the cable. The operation was successfull, soldering OK – but the lens was not working. No contact problems, and nothing wrong measurable.
After complete change of the aperture, was good.


About canonrepair

Ruzsa János. Amatőr fotós, Canon DSLR váz. Amateur photographer. Canon DSLR user.
This entry was posted in Canon lens. Bookmark the permalink.

10 Responses to EF-S 17-85 IS – aperture change – as simple as possible – blende cseréje egyszerűen

  1. Hi cannon Repair, I wass try fix two lens with flex apeture cable broken, but apfter reassembly, an test to the camera, error 01 was appear. really apreciate if you can share your experience about this issue. than kyou….

    • canonrepair says:

      there can be a few possibilities:
      – aperture module died during soldering (after soldering the minimum check is to measure the resistance of the 2 coils, approx 20 ohm. unfortunatelly the position sensor (4 pins) cannot be measured with simple method.
      – cable is of bad quality
      – contact problem in the PCB connector

  2. Machinehead says:

    good guide. I got the cable from ebay. Anyone attempting the soldering of the cable take extreem care. The plastic melts really easiely and teh pins pull out!

  3. daltontribe says:

    Where did you purchase the whole aperture module? I can only find the aperture flex cable for sale. I would like to avoid having to solder a new cable.

  4. Mark says:

    Thank you, much aappreciated

  5. garylijie says:

    My 24-105 got the err 01 problem yesterday. Very sad!

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