Error 99

During my recent trip to India while taking photos, my 10D suddenly started having fits. On a single click the mirror started to slap 4 to 5 times and the mirror was stuck up for ever and would show error 99. It would not comeback to it normal state. I would wait a a few hours after turning the camera off and then turn the camera back on then it would do the same and return back to normal. It continued doing this for two continuous days after which it is back to normal now. I don't see any more problems.

Questions:
1. did this happen to any one else?
2. Do you guys think I should send the camera in for service? It is still under warranty.

Thanks in advance for your replies.

With the same lens each time, or with both lenses? There have been reports here about Err 99 being associated with certain lenses when there was a problem with diaphragm response, which this sounds sort of like. If it's happened with both lenses (in stopped-down, f/8-f/16 conditions, or with the lenses wide open) I'd suspect the camera; if it only, always, and ever happened with the one lens, I'd blame the lens.

this error is quite common and happens for many different, some unknown reasons, including dirty contacts. I've had error99 show up on my rebel with a canon lens once, but turning it off and removing the batteries solved it. My camera did not do the multiple mirror slap and lock up though... you might have some more serious issues.

Do a search for "error 99" and you'll find a lot of posts on this forum about it.

photamat, did Canon ever tell you what your problem was?

The same thing happened on my 20D before the shutter died!

Do you wear a baseball cap?

https://photography-on-the.net/forum/showthre​ad.php?t=126118

I have had the dreaded "Blue Screen of Death" on my Canon 20D several times. Always turning it off, removing the batteries and then rebooting (putting batteries back in, turn on the camera) It seems to work fine. It has happened at such different times, with different lens, that I really can't say what caused it. But the above fix does it every time. I have noticed it does it more with my 28-135 IS Lens. So maybe Canon just has it do it with cheap lens, so you will upgrade to "L" series glass......doubt it!!

I have struggled with a 10D having recurring error 99 issues (for almost the last 6-8 months). On the weekend I went to an event - first shot error 99 EF300 F4 IS plus 1.4x convertor (normally I only have issues on hot days or after long use). Removed TC and just tried 300mm - error 99. Switched to 70-200m f2.8 IS - error 99. Swapped batteries (using grip) - error 99. About to toss the useless piece of equipment..... Getting fed up I took CF card out and put it back in - took photos for the next two and a half hours (including downloading photos to an external drive) with no complaints. Apart from that one time I have never been able to pin the issue down.

Closest service centre is in the next state so I have resisted the 6 week assessment time then fixing period if anything is wrong. If yours is closer I would put it in to get checked out.

I was out today with a 20D and a 100-400 on got the error99. Removed batteries and put back in and now works OK

There was a thread a few months ago about Error99 and sunrise/sunset pictures. What was the subject matter of the photo you were taking when it happened?

sounds an awfull lot like your issue was either the switch on the CF door or the CF didn't seat well.