I have a dual 1gig Quicksilver that has recently quit on me. It shut down one day and now it will start up, run for about 10 minutes and then shut down again. You have to wait an hour or 2 before it will start up again and then it does the same thing. When you press the power button, you can haer some sort of soft clicking sound briefly that seems to be coming from the power supply. This was a used machine before I got it, and it was pretty dirty inside. Could this have in some way messed up the power supply?