Troubleshooting a PSU

[kadean]

I am in the process of upgrading my PC. I have a 500W PSU and case that I would like to reuse from an old build. Something is awry with the old build and I am trying to troubleshoot and basically make sure its not the PSU, the rest I dont care as much about. I am hoping someone here can figure out what is up or at least be certain the PSU is fine based on what I describe.

I have mobo, cpu, ram, and PSU hooked up "pseudo-PC" style like in http://www.youtube.com/watch?v=d_5 [...] =youtu.be. Video card is DVI'd to a monitor. Everything is plugged in to power and the PSU switch is in "off" position. As soon as I flip the switch on the psu to on, boom, everything whizzes up, mobo LEDs come on and the fans on the GPU and CPU start turning. This is without me pressing any button on the mobo or shorting the circuit like in aforementioned video. It just comes on.

Something else of possible interest is the fact that after I turn the PSU switch to on, the "stand by" light on the PSU comes on instead of the "on" light.

Also, it wont post. Nothing happens except fans/leds coming on.

Is it my PSU? Or something else...

Here are the specs if it matters

GPU: 8800 GT 512 MB

CPU: Intel Core 2 Duo E6400 (2.13 GHZ)

RAM: 8GB DDR2

MOBO: ABIT AW9D LGA 775 Intel 975X

Hard Drive: 250 GB 7200 rpm >.>

PSU: Thermaltake 500W
Case: Thermltake Tsunami

 

[kadean]

Update: I just plugged the PSU into the wall and left everything else completely unplugged. When I flip the switch on the PSU the fan comes on and a faint whirring starts inside. Not entirely sure what this means.

Already ordered the rest of my build hopefully I wont have to get another PSU also >.>

 

[bryanl]

A computer will turn on like that if contents of the motherboard clock CMOS memory is incorrect or its battery is weak, even if the BIOS is not configured to turn on the computer automatically after a blackout.