Repairing the 17-85 flatcable: My experience and Nightmare

As some of you guys might be aware of, the EF-S 17-85 has a major design flaw, where the shutter flatcable wears when zooming in/out and eventually it will collapse and break. This has happened to many (including myself) and will probably happen to you sometime (knock on wood).

Canon Brazil would charge me US$ 200.00 to replace the flat cable, what I thought was a bit too high for a lens that I can get new for twice that much, so I decided to risk it and try a DIY approach to fix it.

I found these 3 websites that have been my salvation. I would NOT accomplish it without following them:

http://www.doekle.nl/c​anon_17_85_IS_repair.h​tml
http://www.silco.ee/le​nsfix/
http://thydzik.com …d-zoom-repairdisassembly/

Today I finished the repair and the lens is working again. I have no words to express how proud I am of myself for doing it. It just feels great!

So, if any of you guys go trough this problem at any time, just get the cable from eBay, and if you feel like, do it yourself. It's an amazing experience to see how complex these pieces of engineering are inside.

Now, a few hints of my experience that can be helpful to you:

1- Do it at day. There are VERY small screws in the lens and daylight will help a LOT.

2- Use latex gloves to handle the lenses and have some plastic bags with you. The gloves will avoid fingerprints (SUPER HARD to take off from the inside elements) and putting them on plastic bags as soon as you get them out will prevent dust issues.

3- Have a compact camera with you and PHOTOGRAPH every "layer" of the lens you take off. The pictures on the websites help a lot, but I got lost a few times during the process.

4- Most important thing: MARK THE 3 SCREWS POSITIONS in the front element. These are adjustment screws and if you don't return the lens to the exact same position, it will front/back focus and you'll lose at least a day trying to adjust it (personal experienceops

5- Try it and do it. It's not easy at all, but it's far from impossible. With a little patience, following the website's instructions and photographing the process, it can be done in 2 or 3 hours if you never opened a lens before (again personal experience)

Hope this is helpful to you!

my buddy has a 17-85 that always gets an err now when trying to take a pic. i wonder is this whats wrong

booja wrote in post #11652269
my buddy has a 17-85 that always gets an err now when trying to take a pic. i wonder is this whats wrong

Probably it is the same case. I got this behavior before mine died.

At first he'll get a lot of ERR00 and ERR99 (while the cable is getting broken) and then the shutter will die (when the cable actually breaks).

Is there any way to pre-empt or prevent this problem?

Alex_Venom wrote in post #11652318
Probably it is the same case. I got this behavior before mine died.

At first he'll get a lot of ERR00 and ERR99 (while the cable is getting broken) and then the shutter will die (when the cable actually breaks).

Yup. He was getting the errors randomly. Then it would happen when the lens had the slightest tap against anything it would give the error. Now it's almost all the time.

Maybe I can get it from him and attempt to fix it

Well done. I love doing stuff like this although at the moment none of lenses require ummm...maintenance.

SASman wrote in post #11652564
Is there any way to pre-empt or prevent this problem?

Unfortunately, there isn't. The way Canon projected the lens leads to this since the cable is bent in such an closed angle, it's almost certain it will happen with time.
If you don't use the lens much, don't zoom in/out much, it will take more time, but if they kept the design inside the lens (and I'm pretty sure they did), it will happen.

You've mentioned "shutter" a couple of times - do you mean the iris diaphragm that controls the aperture?

xarqi wrote in post #11654150
You've mentioned "shutter" a couple of times - do you mean the iris diaphragm that controls the aperture?

Yes, that's it. Sorry, I didnt know the word in English

I wonder if all 15-85mm USM's will suffer the same fate?

I bought my 17-85 USM used, now I'm worried. But love it too much to get rid of it!

I just got mine repaired by Canon, even though I am selling it right away. It cost $102 for the repair.

Invertalon wrote in post #11659236
I just got mine repaired by Canon, even though I am selling it right away. It cost $102 for the repair.

So cheaper in the US

Anyone know how much this would cost in the UK? I got quoted £50 for a Tamron with the same problem but got it done under warranty.