MacFixIt reader Peter Wargo describes an strange problem with his Power Mac G5 that was resolved by a simple process documented in Apple's Knowledge Base:
"I had the oddest problem with my Dual 2 GHz G5 - If I removed the side door while it was running (not the shield, just the aluminum door), it would freeze up. I have two at work (identical) that don't exhibit that behavior, and when I ran the Extended Hardware Test, it worked fine. (Boy, do the fans get loud during those tests...) It booted and ran fine with the door removed."
Apple Knowledge Base article #86490 holds the solution. It states:
"When you set up your Power Mac G5 computer for the first time, be sure to remove the four protective plastic strips on the inside of the door."
Wargo says that as soon as he removed the plastic strips, he could successfully remove the aluminum door (leaving the clear heat shield in place) without freezing.