After about three weeks my iMac is back from the shop and perched happily on my desk again. As I had suspected, the problem was a faulty power supply. The fine folks at the mac outpost replaced it and all is right with the world once again.
After about three weeks my iMac is back from the shop and perched happily on my desk again. As I had suspected, the problem was a faulty power supply. The fine folks at the mac outpost replaced it and all is right with the world once again.