Computer turns off before it can boot

[dogert]

My computer started doing this today. When i turn it on the fans spin, cdrom blinks and then like 4 seconds later it turns off. It never makes it to the bios screen. I thought it was a power supply problem but they i tried using a different power supply and it did the same thing. Next i tore everthing out of the case and tried to make it work with just the basics and still did the same thing. I am thinkin its the motherboard thats causing it. Anyone have any advice for me? thanks.

 

[mechBgon]

How about some info about the hardware. If it's an off-the-shelf system, then what brand & model is it.

 

[dogert]

Its a system that i built from a frys deal.

amd xp 2600
ecs n2u400-a motherboard
512x2 corsair 2700 memory
Radeon 9600 pro
xp professional OS

 

[mechBgon]

Originally posted by: dogert
Its a system that i built from a frys deal.

amd xp 2600
ecs n2u400-a motherboard
512x2 corsair 2700 memory
Radeon 9600 pro
xp professional OS

Ok, start with these two things:

1) look at the third pic on this page (good) and the fourth pic (bad). You got the heatsink on the right way?

2) remove the case's power-switch wire from the mobo's pins and just momentarily connect those two mobo pins with a paperclip or other metal object instead. If the system now powers up and stays on, then your case's power switch is stuck in the "pushed" position. When the power button is held down (or seems to be), the system's all "oh, he wants me to turn off " and that's what it does.

 

[dogert]

yeah, the heatsink is on right and i tried the thing with the paper clip and it still turns off after a few seconds.

 

[themusgrat]

Could be the mobo, try with 1 stick of RAM in different slots. Were there any recent hardware changes?

 

[dogert]

I havent changed anything lately. I tried moving the ram around and it does the same thing. I am thinking its the motherboard cause i can even get the bios screen to show up.

 

[AM2]

Read this all the way through I had similar symtoms
http://forums.anandtech.com/messageview...atid=32&threadid=1786386&enterthread=y

 

[AM2]

What I did was start the computer with the xp disk then ran repair, this I thought would fix the problem However after completing the repair computer acted the same way. So I reformatted the Drive and reinstalled. Worked fine! Might be worth a shot

 

[Slowlearner]

Oops double post

 

[Slowlearner]

The symptons you describe are typical of poor seating of heatsink on the cpu. Disassemble and re-seat. Reset CMOS and then boot.

Of course, if the computer was working fine for months and this suddenly started happening then it could be bad cpu fan/loose conn, leaking caps, bad this and bad that. Open up the case and observe carefully if anything is out of whack then systematically check component by component.