40D mirror flicking at random

[thistof]

I just picked up my first Canon, a 40D. It seems to work fine, except for one strange thing. The mirror clicks up and down (very quickly) at random times. The shutter remains closed while this happens, which I have verified with shutter actuation counts via EOSInfo.exe as well as viewing with my own eyes.

I took a quick video of the mirror doing it's thing: https://youtu.be/2mDjai4mlnQ

It seems to happen during the following instances:

*Camera powered on or off

*On battery door open/close (whether the camera is powered on or off)

*Attaching/detaching lens (whether the camera is powered on or off)

*On USB PC connect/disconnect

*At random, every now and then (every 20-30 seconds)

*More frequently at random while tethered (every 8-10 seconds)

*Sometimes when buttons or wheels on the camera are adjusted (this seems to trigger it, but not unless enough time has passed)

This doesn't seem to affect shooting, I'm able to take pictures and everything, it's really just annoying and worrisome knowing that this mechanical part will probably fail sooner than it ought to, and wondering if it's part of a larger underlying problem.

Here are my questions:

What is causing this?

Can it be fixed?

If not, can I safely remove the mirror and use it only in live mode or tethered?

(since I'm really only planning to use this camera with Dragonframe for stop-motion)

[Ray-uk]

Sounds like software corruption, have you tried doing a full reset.

[Waddizzle]

If you can send it back for a refund, I strongly suggest that you do so.  Don't waste your time with a moody camera.  As much as it may hurt, send it back.  Your patience will be rewarded.

The best deals on Canon cameras can be found at the Canon Onlilne Retail Store, in the Refurbished Section.  Canon offers one year a warranty on DSLR cameras and lenses, just like the new gear sold by retailers, including Canon.

[thistof]

Ray-UK, I tried taking both batteries out and leaving it for a while to kill any settingss, I'm not sure if that's what you had in mind, but the problem persists. What about a firmware update/reinstall? As far as I've read I would need a CF card to do that, and I don't have a CF card.

Thanks Waddizzle, I'll keep that Canon online retail store in mind. As for my camera, I messaged the seller as soon as I noticed the problem. They immediately offered a full refund and told me to keep the camera rather than paying to ship it back. Since they were a major camera company, they must know that it's a lost cause, like you said. But I have a free camera on my hands, so I have nothing to lose, I figured I'd see if there's anything I can do to salvage it, risk free, while I look into other options.

[Waddizzle · Accepted solution]

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@thistof wrote:

Ray-UK, I tried taking both batteries out and leaving it for a while to kill any settingss, I'm not sure if that's what you had in mind, but the problem persists. What about a firmware update/reinstall? As far as I've read I would need a CF card to do that, and I don't have a CF card.

Thanks Waddizzle, I'll keep that Canon online retail store in mind. As for my camera, I messaged the seller as soon as I noticed the problem. They immediately offered a full refund and told me to keep the camera rather than paying to ship it back. Since they were a major camera company, they must know that it's a lost cause, like you said. But I have a free camera on my hands, so I have nothing to lose, I figured I'd see if there's anything I can do to salvage it, risk free, while I look into other options.

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That sounds like good news.  If resetting the camera does not clear it, then I fear that camera is useful as source for some mechanical parts.  All of the electronic major parts are suspect, and have to be chosen with care, or not al all.  

[thistof]

Thanks Wadizzle, after fiddling with it some more today and testing with dragonframe, I decided that it would just be one more distraction to worry about when I should be focusing on the actual photography and animation, not minding a technical detail. So I'll probably sell it for parts or something. Thank you for your advice.