iMac Shuts down by itself, help.

[vidkid1]

I've got an iMac, (the swinging arm kind not the newer one). It has been ok since purchased, but recently it has been shutting down by itself. Has anyone else had this problem? I hear it may be a thermal issue, a PRAM issue, an overloaded FIREWIRE bus or USB bus, or the logic board or PSU. Those seem like obvious choices. Im looking for any hard line experiences from anyone out there regarding this.

It shuts down at no particular time length or CPU activity. I could be running Photoshop with some heavy task or nothing could be open and it shuts down.

Any insight would be appreciated.

 

[Didou]

I don't think you'll find many people using such iMacs around here. You can always try the Apple support forums.

 

[vidkid1]

Ooops

Sorry, I thought maybe someone may have such a machine in the back or something. Don't kick me out though, I just finished building 2 customized PCs. with alot of help from Techspot. Thanks anyways.

 

[vnf4ultra]

Which iMac? The g5 imacs had some power supply problems, which would cause some problems like you describe. Most times both the power supply and the logicboard get replaced if that's the case(because a lot of the time the power supply will fry the logicboard). There's a certain range of the g5 imacs that are affected, and if yours is in the range, then you could qualify for warranty repair, even if it's out of the normal warranty period, since it's a known issue.
http://www.apple.com/support/imac/powersupply/repairextension/

Edit: Oh, I see, you must have one of the "soccer ball" imacs. I don't believe they have the same power supply issues that the g5 imacs do.