New build turns on for 5 seconds then turns off

[imported_vor]

New PC build: I turn it on and it powers up for about 5 seconds, fans spin up and everything looks fine, and then it turns off automatically. Pressing the reset or power button have zero effect. Only flipping the switch off and then on on the power supply will restart the PC (which will still only stay on for a few seconds).

I have tried clearing the CMOS, booting without video card, booting with nothing but CPU/CPU Fan, re-seating every cable, all to no effect. Strangely if I boot with the video card in but the PCI-E auxilliary power cable left off the video card, it will siren for the few seconds before the PC turns off.

Also, the 'Standby power' LED on the Motherboard remains Green, even after automatically turning off.

Could it be defective Motherboard, Power Supply, or CPU? Perhaps even the power switch on the case?

Specs are:

MB ASUS M2N32-SLI DLX WIFI AM2 - Retail
PSU ANTEC|TP3-650 RT - Retail
CPU AMD|A64 X2 5200+ 2.6G AM2 2M R - Retail

Any help will be appreciated.

 

[Heisenberg]

Are you sure the heatsink is seated properly? I had a machine do pretty much what yours is doing once. The heatsink wasn't on right so it would run for a few seconds until the CPU overheated, then shut off.

 

[imported_vor]

Heatsink is seated properly; I do not believe overheating is a factor as the very first time I powered it on it shut off seconds later. Even if I somehow 'forgot' to put the heatsink on, the CPU would not overheat within the 5 seconds before power off.

 

[btcomm1]

What type of ram do you have? Have you tried 1 stick of ram at a time if it's ddr? Have you tried known good ram? It sounds like a bad motherboard to me though.

 

[imported_vor]

Originally posted by: btcomm1
What type of ram do you have? Have you tried 1 stick of ram at a time if it's ddr? Have you tried known good ram? It sounds like a bad motherboard to me though.

RAM is:
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X2048-6400C4 - Retail

I tried swapping, using one stick at a time with the same results.

Also, there is a small handwritten in ink "X" on one of the chipset chips, could this be a defective board w/ the X as the marking that somehow slipped through?

 

[imported_vor]

What a pain in the neck RMAing will be if there is no other option

 

[jackschmittusa]

Is the cpu fan connected to the correct connector on the mb? Mbs will shut down in a few seconds if they do not recaive a signal from the cpu fan.

 

[imported_vor]

Originally posted by: jackschmittusa
Is the cpu fan connected to the correct connector on the mb? Mbs will shut down in a few seconds if they do not recaive a signal from the cpu fan.

Yes the CPU fan is connected to the proper connector, and for the brief period of time the PC is on, the CPU fan is spinning. The MB has a 4 pin power connector, but the manual says 'backward compatible with 3-pin fan connectors' if that could have anything to do with it.

 

[RKS]

I had a new EVGA board that would boot for a few seconds and then hang. I replaced/RMA'd the board and that resolved the issue.

edit: I think it may have actually powered off but I'm not 100% sure.

 

[Jeff7]

Originally posted by: vor
Heatsink is seated properly; I do not believe overheating is a factor as the very first time I powered it on it shut off seconds later. Even if I somehow 'forgot' to put the heatsink on, the CPU would not overheat within the 5 seconds before power off.

Oh yes it would.

I know this to be true, at least with a Core2Duo system. I had the motherboard out of the case. It powered down shortly after startup. Those CPUs have a lot of power passing through them. Ever felt a 30W soldering iron? It's pretty damn hot. The CPU probably has a good bit more than that going through a very small area.

But my experience with the board out of the case - I felt the heatsink after it powered down. It felt pretty cold. But the back of the motherboard at where the CPU was? Quite damn hot.
Snapped in the heatsink properly, and suddenly the system booted normally.

Also, there is a small handwritten in ink "X" on one of the chipset chips, could this be a defective board w/ the X as the marking that somehow slipped through?

A lot of components on motherboards have some kind of marking on them; I figure it to be a quality control thing, to indicate that it passed testing.

 

[imported_vor]

I tried starting the PC without the CPU, and it will remain running. However, there are no beeps to indicate CPU is not plugged in. Also, the power supply fan feels very 'weak'. Could it be the power supply is defective?

 

[Jeff7]

Some power supplies only throttle up the fan when the load increases. Judging from the model number, yours is a 650W power supply, and just running the "barebones" setup for troubleshooting purposes, it isn't under much of a load. As a result, it probably isn't heating up much, so the fan won't spin too rapidly.

I think the best way to test the power supply would be to try it with another motherboard if that's possible.