Computer turning off at start up

[Nitrometano]

hi there ppl.. i got a puzzle for u guys help me solve....

My computer is turning off right after i turn on... i hit the power button it starts every fans and leds... so far so good.. then comes the POST beep.. 1 beep (just like normal systems do) after that the display should start but the computer turns itself off..

resuming...

turn on.. lets say 3s
beep once.. turns of right away

1. the sistem is old.. only thing new is the mobo i bought yesterday.
2. this cant be many things.. it beeps like the system is ok..

specs..

proc p4 3.0 ht socket 478
mobo foxconn 661mx
mem 2/512 ddr 400 kingston
cooler zalman 7000b-cu
supply Thermaltake tr2 430w

BIOS specs.

award sis 661 6a7i4fk9c-00 01/22/2005

ver. s661 series 516f1p02 01/22/2005

thats all folks.. if i missed anything.. let me know.

hope u guys enjoy :P

[JANINE]

check all your cables and connections and check all PCI cards.

remove items one by one until you have just a barebones system and see if it starts up then after you remove each item. your mobo should have onboard graphics which wont be a problem

[cguan_77]

check your memory stick...