While I was upgrading my early 2011 13" MBP's HDD to an SSD by the instructions on iFixit, I think I broke my camera cable. When I tried to talk to my friends on Google Hangouts later that day, my computer didn't detect the camera. There wasn't a "no signal" error or anything; the computer just had no idea that the camera exists (but for the record, the microphone still works fine). That was a few months ago, and the camera's never come back since then.
Is there a way to definitively prove that the issue is that I broke the camera cable with an overzealous pull? If it does happen to be a software issue despite all my troubleshooting efforts till now, I'd very much like to know.
Assuming the issue is that the cable broke near the socket, what's the least dangerous way to fix it?
There is a wonderful site "ifixit" that has answers to that question.
The camera cable socket is very fragile. Do not apply any upward force to this socket, as it may break off the logic board. Pull the camera cable parallel to the face of the logic board.
If you are lucky, you did not damaged the socket but just the cable.
Replace the cable to find out.