no post, no beeps

[tmseller]

I would appreciate any help I can get on this one.  I just built my computer and have checked all connections several times, reseated everything a few times and verified my PSU is ok with a PSU tester.  On powering up my lights come on and my fans start running, but nothing happens, including no beeps.  Here is my system:
Asus M2N-SLI motherboard
AMD 3800+ processor
XFX 7900GT video card
Ultra 550w X2-connect PSU
2 Western Digital 250 GB SATA draives
2 G TWINX PC6400 DDR2 800MHz Corsair memory

I've been told by a coupleof toehr folks that it is likely either my motherbaord, or my processor.  Is there a way to tell which it could be?  Both components were bought from Newegg very recently.

Thanks for any help.  Tammy

[GX1_Man]

Much more likely that it is not assembled correctly.

If those are the two options for failure (Mobo and CPU) all you can do is swap them out or RMA them.