asap plz? no picture or beeping noise on boot up

[boogey]

The hardware is. Ultra X2 550W psu, evga 8800gt, corsair 4gb (2 x 2gb), wd c. 250gb hdd 2 of them, cd/dvd burner, e8400, & asus p5k-e (non-wifi). We tested the video card & memory, they work. We know the cpu is compatible. But on boot up theres no picture or beep. Any suggestions? My brother thinks its the mobo. And the psu tester showed everything green.

Thanks in advance.

edit - which does it sound like? mobo or psu's fault? The light on the mobo (small green one). Is lit up.

I'm on my PS3 typing, so.

[Waymon3X6]

It could be that the PSU failed - Ultra units aren't really that great. Do the fans start up too?

[boogey]

The psu didn't fail, the fans work. And its not atx 12v 2.x compatibility issue. The psu is 1st gen. Says it tigerdirect. Could the 1st gen not be atx 12v 2.x?

NVM. Says it meets atx version 2.2 v1.3 standard.

[jimmyz]

Try 1 stick of ram only, get into bios and up the voltages needed to get it stable.