What would cause power light to stay on?

[AuraEdge]

My computer has this problem where it shuts down spontaneously, sometimes when I'm on it, more than often when I'm not. However, when it shuts down, everything goes out except the power light, which for some odd reason stays on.
Anyone know why?

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Details:

I had first thought it was a software problem, First thing I did was a virus scan, and that came up clean.

Then I tried to see if my other partition had the same problem. (Win2k...WinXP Pro is my main partition). It also has the same symptoms so I pretty much ruled out software problems.

I think flashed the BIOS thinking some BIOS corruption is kicking it into standby, but that didnt help either.

I also downclocked the chip back to default with no dice (!700+ TBred was at 2000+)

Basically everything shuts down spontaneously, sometimes corrupting a file like windows/system/config, at which point I need to reinstall Windows to fix it. All my fans and screen output goes out, EXCEPT for the power light. It seems like a standby, except for the fact that pushing the power button cannot wake it up. I need to press the power button for 4 seconds to shut it off, wait a few seconds, and press it to turn it back on.

I think its either the power supply or the board flaking out, or maybe even my primary HDD, but I think it'd be easier to diagnose if I knew exactly what a computer was doing when the power light stays on. Anyone have this problem before, or know how to fix it? It only started happening the middle of last week.

Relavant specs

Soyo KT333 Dragon Ultra Platinum
TBred 1700+ @ 2000+ (Default voltage)
1GB Ram
80GB WD SE HDD (OS's are on this drive)
120GB WD HDD (Storage and backup data is on this drive)
Geforce TI4400 128MB
TTGI 420W power supply. (AMD recommended)

Approx. a little more than 1 year old
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[Steve R Jones]

Do you have sleep mode or hibernate activated? If so, might try turning them off and see what happens.

[SeanC]

Just to be sure, make sure that sleep, standby and hibernate are disabled in the BIOS and Windows.

Does it shut down after a set period of time every time or is it whenever?

Sean

[AuraEdge]

All power management is disabled via the BIOS, and hibernate and standby are disabled in windows. I forgot to mention that.

Also it is whenever. Sometimes itll stay on for a whole 24hrs, and sometimes itll shut down less than 1 hr after I turn it on.

If no one knows whats going on, I'd still like to know which piece of hardware you would try to troubleshoot first.

[joker_927]

Tbred 1700+ @ 2000+ at deafult voltage? You sure that is correct? Has it been running @ that voltage for long?

When I overclocked my prossecor, and didnt increase voltage, my computer would just shutoff, and the keyboard lights would stay on. Weird.

[AuraEdge]

Yep thats right..@ Default. I'll pump the voltage up a bit and see if it still persists. Its been going about 9 months without a problem at that speed, but its worth a shot.

Thanks for the suggestion.

[rpertusio]

Your symptoms reminded me of something. I had a cold cathode light that I installed, and the 'switch' kept shorting out on the case, resulting in the system powering off, except for the power light.
Although very unlikely, you could have a short somewhere (power supply or motherboard, etc)

Might be worth checking out.

- rp

[AuraEdge]

I tried pumping it up .1w, but it still shut down like that.

A short..hmm that sounds very possible. I do have 4 cathodes in this case, so it seems likely thats definitly possible

I'll take a look see when I have some time. Thanks much for the suggestions.