Bad PSU or Mobo? need help, pc won't start.

Hey guys. my desktop turned off all of a sudden one time and won't turn back on and still won't. My first thought, it was the PSU but i think im wrong.

I did the paperclip test and the fan on the PSU DID spin, but it DID NOT spin (but twitch a little) when i did the test while all the PSU connectors are connected, except the ATX connector off course. But i think thats the wrong way of doing it.

So I unplugged all the connectors and did the paperclip test again. The fan spins, then I also test for voltage while the fan was spinning. All the voltage seemed normal (yellow: 12V, red: 5V, orange, 3.3V, blue: -12V, purple: 5V, grey: 5V).

So is it my Asus mobo? it's only been 4 months since i got it (Asus P5Q SE Plus). are there any other tests i can do??

thanks.

it's a Corsair 400CX. here's the link to the site. ill test it on a different system very soon. thanks.

hmmm.....theres only 3 desktop in the house and they all get used regularly everyday so it'll be hard to find the time.

sorry forgot about the setup.
D2C E8400
Asus P5Q SE Plus mobo
Corsair XMS2 DDR2 1066 4GB
Nvidia 512MB 9800GT
Corsair 400CX PSU

i was told the PSU was able to keep up with the setup. I had this since mid April of this year. everything was running great til now.

but i've been running with this setup for like 4 months now. it seemed very stable, even while gaming.

Had you adjusted anything in the bio's? Try resetting to default bios settings. Also check for a bad ram module after you do your reset.

I'm not sure without having seen it. I'm just saying it is a good place to start before an RMA of the board. If resetting the bio's does not do it and the PSU checks out than next is ram then M/B. Let us know.