Here's the situation: Stuck a hard drive in my Powermac G4, connected it, put in a Tiger install disk, everything running smoothly until WHAM! I leave the room for 3 minutes, and it turns itself off. It was in the process of installing, so don't know what damage its done. Nobody touched it. Can't figure out what the problem is. Connected to my HDTV with an DVI to HDMI connector, not that it would make much difference, as it was working fine before. Now, whenever I try to power it up, I hear the chime but then no image shows. A bit baffled.