XP2000 + Elite ( :mad: ) Motherboard, powers up for about 2 seconds then shuts off, any ideas b4 I start ordering parts ?
I recon its psu or cpu getting hot
have you built the system yourself, how old is it, and have you touched or added or taken out anything inside ur pc?
2yrs old and its untouched
PSU I bet, Sounds like power good signal.
or could be the CPU heat sink fan has died, open ur case and when you turn it on, see if the cpu fan comes on when it doese come on or 2 seconds.
also why ur at it, make sure all the power leads are conected, and that the heat sink is tightly secured to the CPU
cpu fan spins, power leads all connected
i just had somehting like this a little while back on my main system . Ended up being the psu but it wasnet totaly shot . mine hads 2 power bundles comeing out for the drives if i ran anything off one bundle set system would power up then powerdown . but if i ran everything off the othere power bundle would power up just fine . still useing the PSU but im pretty sure il have replace it in near future .
Its a cruncher…
will be soon back up with a new case 
I had a power-on problem with a DELL. The CMOS RAM was telling the BIOS that the PC was supposed to be hibernating. On power-up, it took a second for the code in the BIOS to wake up before it queried the CMOS RAM (and then started the long sleep).
I fixed my problem by grounding a security jumper on the mother board that restored factory settings.
This may not help, but…
–Tom
My money says the CPU is overheating and the motherboard is shutting it down. The PSU is my second choice.
Try cleaning the dirt out of your heatsink. After two years it’s probably pretty bad. The PSU is probably ok. 
In the 2 seconds it’s on do you get anything on the screen? if you do then it’s gonna be a heat issue, if you don’t it’s gonna be a power problem.
my2p