I was wondering if anyone could help me out with this. I recently purchased an Xclio 450w PSU from Newegg along with an Athlon64 3000+ and EPOX EP-9NDA3J nForce3 ULTRA mobo. When I hooked everything up the mobo powered up for a 1/2 second and then shut down. I made sure everything was connected properly and tried another couple of times but nothing. I then hooked up my crappy Raidmax PSU that came with my case and everything worked great. I though maybe my PSU was defective so I RMA'd it to Newegg. Just got the replacement and tested it out and the same thing happened. Power for a millisecond and then shutdown. Does anyone have any suggestions for me...please!!