I'm definitely not an expert but I have general knowlege from building a couple systems. My current system is the following (I apologize if some details are left out, I'm currently at work) OS: Windows XP Chip: Intel P4 MB: Asus P4P800 (865 PE) RAM: I forget - 2 sticks of Kingston = 1gb HD: 2 SATA Video: Nvidia 5600 AGP (running 2 monitors) PSU: Generic from Fry's 400w I was listening to some streaming music and left the room for a couple minutes and came back my computer had shut down. When I got closer I could hear the system trying to boot, the fans would spin but it would shut down every 2-3 seconds. I switched the power off from the PSU. I bought a replacement 500w PSU from Fry's figuring it went bad. I installed the new PSU but the system would not boot. THe fans would come on and a light on the MB was on but nothing. My monitors weren't receiving a signal either. I then thought maybe it was the video card and went and bought a Nvidia 6800 AGP but still nothing. I read online and tried a few other things: - Removed the onboard battery on the MB and reseting the CMOS using jumpers - Removed all PCI components including video card and tried booting and then installing only the video card and rebooting. - Removed one stick of RAM - Removed hard drives At this point I think it might be the MB or just another bad power supply. Any other suggestions? Thanks in advance.