iMac shuts off at random
My 17inch iMac G5 will randomly power itself off.
At first i thought it was overheating, so i opened it up and cleaned all the fans and vents to make sure there was no excessive dust and that they all spun freely.
I put it back together, and i've noticed that sometimes i'll power it on and it'll shut itself off after 5 minutes, other times it'll allow me to capture a video from my camera, convert it, and then burn it to disk.
Sometimes it'll happy run for a few hours, or even a few days, other times it'll not last the aforementioned 5 minutes.
Because of the mass variance in uptime, i'm not convinced its a PSU problem. Because i was able to get it to work pretty hard with the video capture/encoding/burning, i'm not convinced its over heating. plus, after having laid eyes on the cooling components myself, and having given it a jolly good clean (not that it really needed it), i'm even more convinced its not an overheating issue.
I reset the PMU and PRAM after reading about it online, but it still occurs.
I'm at a loss, and not really willing to take it to someone to get charged an arm and a leg for an overly simplistic diagnosis of faulty power supply.
What say you?
Is this a good question?