Powers on from psu wont display

[Dan4451]

Built a system a while back and I seem to be having an problem which I expect it to be caused by either the evga H55V mobo, or the 600W rosewill psu.

The system powers up but it powers up as soon as I switch on the PSU from the back (not from case button). Fans spin, hear the hdd whirring, the disc drive operates, but there is no display.
I listened for a speaker beep and heard 2 short beeps meaning a parity error.
So I tried the two different sticks in different slots and now I wont get a speaker beep but still no display.
I tried popping out the cmos battery for a few minutes.

cant get it working any ideas?

 

[Dan4451]

I tried swapping out the psu with another one. now none of the fans work but the 5VSB light on the motherboard is lit up.

 

[smorizio]

if the mb has onboard video see if the gpu went bad and the mb is using the onboard video port. also if there no video try removing the video card and see if there any video from onboard gpu or try another video card.