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:
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!