Asus p5ke no power?

Okay.. long story short. Starting having problems with my last motherboard not posting and then it started only powering up for 20-30 seconds at a time, did a ton of trouble shooting with some friends and got a new mobo.

Now I've got this new mobo and I hooked it up tonight.

I couldnt get it to power up then I remembered to plug in all of the system panel stuff. Duh..

Still cant get it to power up at all. But one time randomly it DID, only to shut off after a little bit.

Rest of setup is : Quad core CPU(can get all the info if its needed) and an 8800. Memory is OCZ. 4 gigs of it. hard drive, sound card are not in.

I'm really thinking its my power supply. The motherboard's light always comes on, but nothing turns on when I hit power, except for the one time where it turned on and gave me the 'no video card' beeps, plopped the card back in and havent gotten it to power up since..even after trying it without the card a couple times.

Unless I managed to mess up the motherboard somehow while installing it (ESD or something, which I really dont think I did), I imagine its my power supply.

How much watt or old is your power supply? You might test a new power supply. Check here : Power Supply List

It's an ultra X connect 550 watt