if it isn't PSU related, clear the CMOS (remove battery, bridge jumper, whatever your motherboard's manual says), then try booting up again and see what happens.
If still no go, check for leaking or bulging capacitors on the motherboard.
If everything checks out fine, get a PSU tester or swap out PSU's with a known working one.
Disconnect ALL unnecessary peripherals leaving only 1 stick RAM, video, keyboard and mouse.
Power on again and see if it works.
If no go, you have a dead motherboard.
This post has been edited by Alex548: Apr 26 2010, 02:15 AM