Computer won't turn on anymore, random occurence

[kabalcage4783]

My computer was working properly and then I turned it off. I later came back an hour later and it won't turn on anymore.

I have
GA-K8NSNXP-939
A64 3500+
A gig of OCZ ram (I have done memtest86 for 8 hours, passed)
550w Antec True power
6800U

When I press the power button nothing turns on, not a single sign of it working.
I tried taking off everything except 1 stick of ram and the videocard. The drives are disconnected and it still doesn't boot.

I tried using another computer's working power supply in my comp, the computer still showed no signs of life.

If I recall correctly, on the mobo there's a little LED next to the ram that was on (when the power supply was turned on). That led isn't on either when the power supply is on.

I've tried everything I can think of. I'm guessing it's the motherboard. Any ideas?

 

[kabalcage4783]

Please, any ideas?

 

[BadThad]

Did you try manually jumping the "pwr switch" connector on the mobo? You just need to eliminate the switch as the possible cause. If it doesn't power up after that, then it sounds like the mobo is indeed bad.

 

[CrispyFried]

Ive found on several different comps over the years that when that happens (rarely) you can power it up by holding the front power button down and cycling the rear ps switch, or unplugging and plugging the cord of the ps (again holding down the front power button) if the ps doesnt have a switch.

I have no idea why that works or what causes it not to power on normally in the 1st place though. Buts its worked several times.

One comp that the above worked on even had a led on the mobo that lit up when the front power button was pressed so I knew the button worked, it just didnt want to turn on till I did the cord trick.