Drebel Er-99 fixed

[Hellashot]

A week or so ago I posted that my Drebel got stuck on an Er-99 where the mirror seemed to not be able to drop down into proper position. Looking through the viewfinder was dark and re-inserting the battery didn't work. The error started when I had my Sigma 24-135 on which has been on my camera for several weeks now.

Right before I was to package my camera up to ship to Canon, I decided to take Canon's last piece of advice (from emails) to run a clean eraser over the contacts on the camera/lens because "sometimes 3rd party lenses cause this error" - Canon. Even though I didn't mention I had a non-Canon lens on. But I didn't think it to be of use when I first read it because the mirror would not drop down when there was no lens mounted. I ran my clean finger over the contacts, put the kit lens on and it works just like normal.

When talking with my brother, he said the reason that 3rd party lenses might cause problems is "dissimilar metal corrosion" When 2 different metals are in contact they will "rust" at different rates. (not that internal points in a camera will actually rust but may wear and corrode in very small amounts at a different rate) Dissimilar metal corrosion is a real phenonenom, and it is possible that different lens makers might use a slightly different alloy for its contacts. I am going to start leaving a Canon lens on my camera when I know I might not be using it for a week or more to guard against this. I've heard that Radio Shack sells a cleaner for contacts (and no not the ones that go in your eyes, lol).

Just thought I'd let everyone know this since I didn't get any suggestions on here that deal with the contacts.

[KenW]

Thanks Hellashot, I will keep that fix in mind and maybe save someone else the trouble you went through.

Ken W. :D

[robertwgross]

When talking with my brother, he said the reason that 3rd party lenses might cause problems is "dissimilar metal corrosion" When 2 different metals are in contact they will "rust" at different rates. (not that internal points in a camera will actually rust but may wear and corrode in very small amounts at a different rate) Dissimilar metal corrosion is a real phenonenom, and it is possible that different lens makers might use a slightly different alloy for its contacts.

This is a great concept. Unfortunately, the lens-to-body data channel contacts are gold plated on the lens and on the body. Gold does not rust.

It is possible to wear off the contacts, partly by many lens removals. However, done properly, this is many, many removals.

Most of the third party lens incompatibility was a data incompatibility, not something in the lens contacts. This is proven by the fact that Sigma replaces a chip in an old lens and brings it back to being compatible.

---Bob Gross---

[Hellashot]

But you can have differences in the same material made by 2 different sources that get slightly out of sync. Canon basically acknoledged it, not in the same words I used. I still suggest keeping Canon lenses on a Canon camera in storage.

[Mark_48]

Glad to hear you got things working properly. My first inclination would be to use a cotton or foam swab dampened (not drenching wet !!) with a contact cleaner specifically made for electronic equipment. Caig makes products specifically for this, although a bit pricey http://store.caig.com/s.nl?alias=caigstore . Treat the contacts as you would the glass on your lens. Don't touch with your fingers - your fingers have bodily oils and salts on them that potentially could deteriorate the connection and corrode the gold contact plating. Also the salts could cause a conductive "bridge" between contacts and cause problems.
While you've got the contact cleaner out, it may not be a bad idea to give your battery contacts a wipe as well.

Should you use an eraser to clean the contacts, use only a very light pressure and be very careful to not get any eraser bits into the body of the camera. Over time, concievably the gold plating could be worn down using an eraser, so it would be best to keep cleaning this way to a minimum if possible and not do it as routine.

Mark....

[cfcRebel]

Thanks Hellashot. I'm drebel user and i'll keep that in mind. ;)

[FastPics]

This is a great concept. Unfortunately, the lens-to-body data channel contacts are gold plated on the lens and on the body. Gold does not rust.

It is possible to wear off the contacts, partly by many lens removals. However, done properly, this is many, many removals.

Most of the third party lens incompatibility was a data incompatibility, not something in the lens contacts. This is proven by the fact that Sigma replaces a chip in an old lens and brings it back to being compatible.

---Bob Gross---
The lens contact suggestions are usually spot-on for cameras.
However, I think I figured out my SIGMA 28-135/Rebel err-99 problem.
Not definitive proof yet, but all symptoms point to a flexible circuit (flex circuit) connection that is used inside the lens to connect two circuits on two barrels in the lens.
My error ONLY occurs when I zoom through ~45 (either direction). This just happens to correspond to a "kinking" of the flex interconnect ribbon that I am sure is not supposed to be there. I can see it kink!
I work with these flex circuits all the time and they are supposed to be used in smooth-roll-over mode, not in kink-it-to-bend-it mode.
I have used this camera/lens combo for over 1-1/2 years under heavy shooting (many thousands of sports shots), but almost always at one extreme of the zoom or the other.
Just recently I changed shooting practices, requiring more zooming in and out. This problem did not show itself until I changed zooming practices.
No effect from flash use, contact cleaning, camera mode setting, auto-focus. If I am at ~45 even turning the camera off, then on does not clear the err-99.
I hope this helps someone.

Now to the question of the day. Where should I send the lens to get it repaired? I bought it new from B+H. Any suggestions?

[Mark_48]

The lens contact suggestions are usually spot-on for cameras.
However, I think I figured out my SIGMA 28-135.......

Now to the question of the day. Where should I send the lens to get it repaired? I bought it new from B+H. Any suggestions?
Would this work ? :)

http://www.sigmaphoto.com/sigmaonlinemall/ebay_service.asp