Hello, I admit I am a Mac idiot. I am Systems Administrator and technical savvy when it comes to PCs but don't know a lot about Macs. I recently saved a G5 from the trash bin at work and wanted to use it at home. One of the Mac people in our IT department loaded a fresh copy of Leopard on it and it was working fine at work. I brought it home and plugged it up and it makes it to the white screen with the apple and the spinning wheel and then it just shuts down. I tried everything I could find on the internet. Reset PRAM, checked the hard drive, different keyboard and mouse and several other things. I decided to take it back to work and had this person reinstall the OS. We have determined that it is not a failing hard drive or memory because we have used different ones for both. Anyway we reloaded the OS and while at work I rebooted it several times and a couple of times pulled the power cable from it so that it was completely off of a power source and every time it booted up fine. So I brought it home and after it being unplugged for a couple of hours it did the same thing on boot up where it would get to the white screen and die. I changed out the PRAM battery just for the heck of it and no luck. What I have determined is that for some reason when this G5's OS is reloaded and it is at my work on power there and only off of power (unplugged) for a few seconds it boots up fine. When it is unplugged for an extended period of time it will not boot up. Something about it being unplugged for a period of time makes it lose something. Does anybody have any other suggestions on what I could try? Thanks!