Hey everyone. I think my iMac is on the way out. It turns two years old in 3 days time and I don't know if it's going to make it. I've been having random power failures with this machine. This morning I woke up tp find that it was off. I attempted to turn it on a number of times. The computer would turn off sometimes when the start up chime was playing, or at the log on screen or even just after I had logged in. I'm workingon it right now so it hasn't turned off for 15 minutes or so. Not really sure what to do. My guess is that it's the power supply. Might give apple a call tomorrow. I don't have apple care so if I want it fixed I'll have to pay a lot for it. I was just wondering if anyone had any advice, other than to back up all my data. Or if anyone in Australia has had their power supply replaced, how much did it cost? The specs are in my signature. And I forgot to mention that it's a Rev B and doesn't fall into the serial number range for the logic board replacement program.