Computer shuts down during boot

[Xao]

I'm putting together a new machine for the first time in several years. My problem is that while the system will begin to power up, it shuts down roughly 5 to 7 seconds into the process. This seems to coincide with the HD spin up, but this could be illusory. There is, as of yet, no OS installed.

System specs:
Chip: Athlon XP 2600 +
Mobo: ASUS A7N8X
RAM: 512 Meg Kingston DDR
HD: 80 Gb IBM 7200 rpm
Vid Card: Radeon 9500 Pro
Toshiba DVD/CDR drive
Sound Blaster Live

Any help would be greatly appreciated!

 

[franklin97355]

By shutdown do you mean power off?

 

[Xao]

Franklin,
Yes, the system powers down entirely.

 

[smah]

Make sure your processor fan/heatsink is mounted correctly and working.

 

[abeza]

I have in the past, had a similar problem with
a new system I was assembling. The power supply
shut done seconds after switching the primary power
on. My problem was caused by two problems, a defective cpu
and a defective power supply unit. Replacing both the cpu
(Athlon XP 2200), and power supply resolved my problem.
Try replacing the power supply first, if the problem still occurs something is shorting out the power supply, in my case it was a defective cpu that had an internal short. Switching power supplies are short circuit proof and the power supply output should recover after the short was removed, in my case the power supply did not recover after the short was removed by installing a good cpu. I am sure my original problem was caused by the cpu. My original power supply should have been able to recover after the short was removed but did not, so I had to also replace the power supply.
abeza

 

[Xao]

Ouch, that's really, really not what I wanted to here Abeza, but thanks. Any thoughts on testing this without springing for another chip? I can pillage an old computer for another power supply, but don't have another Socket A chip handy.

 

[abeza]

Hi Xao,
give this a try, remove the cpu then apply power to the system and see any of the fans operate. If they do, this is a quick test indicating that the power supply is functional and the cpu was dragging it down.
If, you have a voltmeter measure the voltages on the
power connector at any of your devices such as harddrive, cdrom drive etc. the yellow wire should measure +12vdc, the red should measure +5 vdc with respect to any one of the black wires, this connector should have four wires, yellow, black, black and red (If the fans don't operate, I am sure you won't measure any of the voltages on the power connector). If the fans fail to operate with the cpu removed, this is indicative of another component associated with the motherboard is defective or the power supply is defective. It might be easier just to initially substitute the power supply and if that does not resolve your problem, then go the route of removing the cpu as I have indicated above.
abeza

 

[edfair]

How about pulling the power on switch connector from the M/B and try starting it with a screwdriver blade. May show up a power on switch problem. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[Xao]

Well, pulling the chip allows the fans to operate beyond the point at which the system usually shuts down. I guess either I have something wired in such a way that the chip shuts it down, or NewEgg shipped me a bum chip.

 

[Xao]

Thanks for the tip, Edfair. I went ahead and did as you suggested, but came up with the same result. Anyone know if the ASUS A7N8X has any sort of protection feature whereby it kills the power if certain components are absent or connected incorrectly?

 

[edfair]

How about pulling power from everything but the M/B? Sounds like the power is falling short of what is needed and running the M/B alone should extend the time before it powers off if it is a power problem.
This isn't a solution but may help diagnose the problem. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.