04-05-2008, 05:00 PM
I've seen lots of iMacs with similar problems. They've got defective temperature sensors and PSU's. Apple's quality control is bloody awful these days.
Run the hardware test from your install DVD (insert disc, restart, hold down "D" key during startup) while your iMac is still warm after one of those restarts. Sometimes it'll turn up something.
If not, you have my deepest sympathies...
Because it's an intermittent hardware problem, the Apple Hardware test and Service Diagnostics discs aren't likely to turn anything up. People usually have to bring their machines into the Apple store several times, facing obstinate and downright rude "Geniuses" who don't know how to do anything more than run those tests and will act like you're imagining the whole thing.
Run the hardware test from your install DVD (insert disc, restart, hold down "D" key during startup) while your iMac is still warm after one of those restarts. Sometimes it'll turn up something.
If not, you have my deepest sympathies...
Because it's an intermittent hardware problem, the Apple Hardware test and Service Diagnostics discs aren't likely to turn anything up. People usually have to bring their machines into the Apple store several times, facing obstinate and downright rude "Geniuses" who don't know how to do anything more than run those tests and will act like you're imagining the whole thing.