Can't get new mobo to POST

[RPA]

I built a new rig yesterday but I can't get it to POST. It acts like a bad proc but I swapped them (3200+ Winchester)and it still wouldn't do anything. The mobo light is on and the exhaust fan only has power for a second after turning on the front power switch. I was hoping that someone maybe has been through a similar thing with this set up or can offer some advice.

4400+ X2
ASUS A8N-SLI Premium
2 gigs of Corsair XMS
Raptor HDD
Antec PERFORMANCE TX TX1050B case (500W PSU)

[Magnj]

Welcome to XS. I know it seems retarted...check the basics. Unplu, and replug everything, clear the CMOS, check battery. Make sure all your IDE cables and such are actualy functional. Make sure RAM is in correctly, etc. Gotta be something real basic or somehting is dead

[NickS]

Yeah definentally clear your CMOS. Make sure the Mobo's mounted correctly...also.

Make sure you have all the required standoff's, and or make sure you don't have one too many .

[RPA]

Thanks for the welcome and suggestions. I did clear the CMOS before hand. I just checked and verified that the RAM and HDD are good. So I think I narrowed it down to either a faulty PSU or mobo.