I've tried all this advice
To avoid the "been there done that" response, please tell us all the "advice" you have tried.
http://support.apple.com/kb/HT2090 How to Troubleshoot iSight
Err, sorry - "all this advice" because when I searched the Apple site for iSight troubleshooting, I got this link:
Which had a thing at the bottom saying "ask other users about this article". I clicked it, typed in my problem, and it came out as a forum post. I had no idea it wouldn't be linked to the support page! So, "all this advice" refers directly to the advice above the box in which I typed this message. My fault for not realising it would come up as an unlinked forum topic? Or Apple's for not making that clear? Sorry for the confusion.
So, anyway, I've tried all the advice on the above page, and nothing works. I've upgraded to Mountain Lion, and still have the same problem.
Well done, Boomer. The application-specific, user-specific, iSight recognition, and SMC or PMU reset suggestions in your "Troubleshooting" link are certainly the first things iS0krates should try for these problems.
If the problem continues, I would suggest that an Apple Service Provider evaluate the problem & strange S/N.
I may continue to offer an occasional post here, but you are doing a great service in iSight. Keep up the good work!
I thought I made pretty clear in my last post that I've tried all the stuff on the advice page - and that I knew of the existence of the 'troubleshooting' link - it's that page that led me to create this post (so, no offence, but I don't see why it's helpful to give me a link to the very same link that appears at the top of this page, it being the thread whence this discususion emanated)! I always follow all the documented troubleshooting advice I can find before asking on a forum...
Anyway, you're probably right about taking it to Apple. I'll do so tomorrow.