Help! Built new PC

[Draxxus]

Hey, I just built a system with the following specs:

P4 3.0ghz 800mhz fsb
512mb pc3700 kingston
Intel *D865GBF* motherboard
gainward geforce fx 5900
Turtle Beach 7.1 sound
450watt psu
buncha cd roms/rws and floppy stuff
dual 120gb seagate 7200rpm hds

Now here's the prob:
I JUST put this all together. I plugged it in, and turned on the psu. When I turned on the psu, everything powered on for oh, .8 seconds, then turned off. Start button doesn't work, it's as if it is not plugged in. The little LED light on the mboard continues to shine green though. Unplug psu, plug it in again and switch it on, does the same thing.

I'm thinking the motherboard is broken somehow. What you think?
Thanks!

 

[XT]

i dont think nit would be your mobo as it has lights on. Does the hole systme turn off or just a select few items? try to see if your heat sink is seated properly. other than that unless you give me a specific description of whats happening thats all i can offer. Give more details and more help will be provideed step by step

 

[Draxxus]

the heatsink looks fine because there's thermal paste covering the entire cpu. I dont think its on long enough for the cd drives and hd to power up, because i cant hear them. All the fans and led lights throughout the case, including the processor fan spins normally for less then a second, then everything powers down.

 

[Draxxus]

just tested it again, the cd drives do turn on because the led light on them flickers too for a second after i turn on psu

 

[XT]

sounds like a faulty psu to me. because take a look at it the hard drive cant be it the cd-rom cant be it floppy cant be it video and sound cards cant be it so that leaves cpu,mobo,psu. check all connections to and out of mobo. And re-seat your h/s. if that all works its psu or cpu. If it was cpu it would be over heating in this case and shutting off and if it was psu the systme would fail almost right away??? so try testing psu or cpu out in an other machine that should tell u