I have a G4 Quicksilver 733 that has gone through two motherboards since March '02. Yesterday it seems that it has taken it's third. Here's the scenario: Push power button, get startup chime, fan and hard drive spin up. That's it. I had it diagnosed and serviced at an authorized dealer/service center the first couple of times and it's there now waiting for someone to check it out. The first two times it was covered under warranty but now the warranty's up and I'll probably have to eat it. Anyone else have this trouble? Is there any way to diagnose what is causing it? Any help would be appreciated.