So a few weeks ago my camera stopped working. The UI comes up but the screen is black. I was running cssu testing and power kernel. I went threw the whole f cam drivers / restore the stock kernel which worked the first time this happened a few moths ago.

This time it didnt, so I reflashed the device and when I open the camera app I get operation failed. I have also reformatted the device as well.

I think it is the hardware itself. The last thing I did was use the flashlight app, when i used it it made a loud click almost if there was a shutter. I'm wondering if there is some type of shutter or anything that could be serviced in order to get it working again.

You can buy a replacement camera module and replace the one in your N900 with it, if it's a problem with the physical camera that would fix it.

i'm also having the exact same problem with my n900. hope someone can help resolve this issue

Does it work with third party applications (BlessN900, FCamera..Panorama)?

I had same "operation failed" problem with N95 but it worked just fine with other applications like bar-code reader. Solution was to detach camera module from motherboard...and after 3 days attach it again.

Flashing, changing software versions and other things didn't help.

It didnt work with any apps neither did the front camera. I just removed it following this

http://talk.maemo.org/showthread.php?t=66457

I used two pieces of plastic that i cut from a blister pack instead of a razor blade. One at the top and one at the bottom, slid the module out really simple. I flicked the module with my finger a few times. You can hear something on the inside move. I reassembled and now my camera is working again.