I replaced the LED for a client and afterwards, upgraded the computer to 10.8. It is a white unibody macbook from about 2009 or 2010. Because of the work I did on the screen my first assumption was that something had become disconnected, but as I looked around, I got suspicious that it might be a software problem as lots of people have had the same problem after this upgrade. I have tried resetting the SMC and the PRAM. I checked the connector on the iSight camera at the top of the screen and all appears OK. I can't find any reference to where that connector terminates on the motherboard, though, so make sure I have it secure. The camera does not work in multiple applications. It also doesn't show up in the system profiler under USB. Any ideas about anything else to try? The fact that I replaced hardware AND did a software update makes it tough to tell which is the source of the problem. Thanks! EDIT: FYI I pulled the thing apart again and reassembled it and it's now working. I'm pretty sure that one of the 3 ports that iFixit calls the wifi/bluetooth antennae is actually the USB for the webcam. You can't follow the cables all the way without doing some excessive disassembly, so I can only assume that since 3 cables go into the base of the screen and 3 come out, that they are the same 3 before and after.