I just bought a 27" iMac off of Craigslist, 2010, and it was sold as not complete and without a hard drive. I opened it up and was struck by the fact that everything appears to be in order, it has 16GB of RAM, and only the hard drive is missing. There were quite a lot of screws missing (only three holding on the panel, should be 8), and the isight was dangling loosely... When I first received it, i tried to boot it up. No dice. Nothing at all. No beeps, no whir of the fan, just as if weren't plugged in. Figured that might be related to the hard drive missing, so I put in an old one that has OSX on it and still nothing. I'm concerned that perhaps the Power Supply isn't working properly and/or needs replacing? What should I be looking for in something like this? All cabling looks intact, and if not for the hard drive, I'd think it was A-OK. I know if I can find the source of the problem, I would be able to fix it. Thoughts? (EDIT) The only sign of life from the machine is the HEADPHONE jack emitting a red light. Hm.