New pc...power won't stay on.

[algae]

HI all,
Just put togther a new pc built on a P5K mb, 6600 quad core cpu. Got everything in place, press the power button and the CPU fan starts, but quickly shuts off -- nothing else happens. No HD whirl, nothing. There is a green light on the motherboard when I plug it in though.
This also may help...I swapped out the 450w power supply in the case (Antec Sonata II) for a new Silverstone 600w. When I disconnected the old one, I noticed that a connector that ran from the power supply to the mb..it's labeled "pwr_fan" does not have the same connector built into the new power supply. This may be the problem but I'm not sure what to do about it if the new power supply just doesn't have that connector.
Thanks for any help.
Gary

 

[LOUISSSSS]

u shouldn't need to connect the "pwr_fan" i never did. do u even get to boot into the bios? if no, then it is prob a hardware problem. try 1 stick of ram in the first slot first, then continue with trial and error with the ram sticks

 

[DSF]

Did you try the computer with the included 450W power supply? That would help determine whether or not the power supply is indeed the issue. At any rate, it's not a problem that the power supply doesn't connect to the PWR_FAN header on the motherboard.

 

[LOUISSSSS]

Originally posted by: DSF
Did you try the computer with the included 450W power supply? That would help determine whether or not the power supply is indeed the issue. At any rate, it's not a problem that the power supply doesn't connect to the PWR_FAN header on the motherboard.

it is, if u got into the bios and set the pc to not boot up if the "pwr_fan" isn't connected, but it should still be able to go into the bios... right?

 

[jackschmittusa]

Sounds like a case short. Did you test the new parts on the bench?

 

[Paperdoc]

Maybe an automatic overheat protection system is getting you. Most systems will monitor the actual CPU temperature and shut down if the CPU gets too hot. If your system actually is working properly but the CPU fan/heatsink system is poorly mounted and can't cool enough, the CPU will overheat in 5 to 15 secs and shut down. On the other hand, this is all controlled by mobo and BIOS, so if they are faulty, they could believe the CPU had overheated when it has not, and you'd get the same result.

The other system, again through mobo and BIOS, monitors the CPU fan speed and shuts down if it fails. So check that the connector from CPU fan to mobo is plugged in properly; otherwise it could decide there is no CPU fan speed and shut off fast.