Problem with MB, PSU or tower power switch?

[ik694]

I just built a new system thats going to be for my mom for christmas:

Ive got a

AMD Phenom 9950 BE
MSI K9A2 Platinum MB
and an Antec 500W Earthwatts Power supply
in a Coolmaster Centurion 5 tower.

Here is the problem i have. Ive hooked everything up, the LED on the MB lights up, but when i hit the power switch on the front of the case it doesnt turn on. I tried shorting the two power switch pins on the motherboard with a flathead screw driver and still nothing. I assume that means its the board, but i was open to any ideas before i take everything off the board and RMA it.

Thanks

 

[ik694]

Does anyone have any ideas, I just want verification that my diagnosis is either correct or if something else could be the cause.

 

[doubledogdare610]

It may be the Psu,
to turn on the psu manually on the psu 20/24 pin connector, use a paperclip or wire to connect the pin on the green wire to either of the ground pins (black wire).
then switch on the psu.
if the power supply powers up,
then it is a MB problem.

 

[Obbyb1]

Try what doubledog said, or try a completely new PSU if you can find one.
Alternatively, search your board for any blown capacitors.