I have a G5 iMac (no isight) that has gotten much louder than when i bought it a couple years ago. The fan sounds almost like a jet engine. Yesterday the ethernet plug stopped working completely and today it has started powering down on its own at random. It powers off even when no programs are running and while it is on the log in screen. Any thoughts about what it might be before the 2 hour apple support call? The last call only resulted in me reseting my p-ram whatever good the tech guy did there was not noticed.