Comp restarts random, pwr button 5 sec doesn't shut down?

I_coNer

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Jan 1, 2005
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Hi there.
I'm not a computer newbie, I've assembled my own system and have had it overclocked where it ran perfectly stable for about a month. My specs are the following;

C2D E6600 @ 1.325v
2GB Crucial Ballistix PC-5300 DDRII
Asus P5W DH Deluxe
Chill Innovation 520W
Leadtek px7600GT

Lately my system just started rebooting at random times. It does this even if the computer is just idling in bios. At some point it just restarts. I thought this could be due to the extremely hot temps we have where I live atm so I completely reset the cpu, ram and mobo to default speed and settings. This didn't help. It still reboots, and I've monitored my cpu temps - they're completely fine.

After I reset my bios settings, the system now won't shut down at all either. Holding the power button for 5-10 seconds doesn't shut down the system like it used to,but instead it restarts the system after the 5 seconds and then it just keeps being in the pre-boot state (all fans etc on full power, but no image on the monitor or hdd activity) - after it goes into this state I have to push the power button (again) and THEN it goes into the boot state. The same thing happens if I choose "shut down" from windows, it just restarts into this pre-boot state where every fan is at 100% - before the pc began restarting randomly, it would go into this state for a few seconds and THEN by itself go into the boot state, when i resatarted but it doesn't now..

I read that it might have something to do with ACPI settings in my bios - but I'm not sure what to change tbh. I just can't understand why holding my pwr button for 5-10 seconds doesn't restart the system?

I ran memtest sucessfully for 1 hour with no errors. tried replacing the memory modules and it still reboots so they seem to be not the problem with the random restarts.
 
I would try reinstalling the video driver. I might try a system restore to a point before the problem occured. As far as hardware is concerned, I would replace the SATA cable to the OS HD. I would try one DIMM of RAM in slot one an see if the problem went away. If I couldn't find the problem, I would do a reinstall of the OS system. Sounds like a driver issue or possibly a registry issue.
 

I_coNer

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As I stated above it has nothing to do with the OS afaik? What happens in bios != responsibility of Windows. If it restarts from bios it's definitely hardware or wrong bios configuration.

Anyway I haven't had a restart for several hours now - I updated the bios to 2004 (beta release) and that seems to have fixed it. I won't know until a few days has passed though.

I'm still having the problem of it not shutting down though. I've unplugged everything I can; harddisks, sound card, network card and the only things plugged in right now is: power supply, cpu, ram, and graphic card. It still won't shut down when I press and hold the power button - how on earth do I fix this?
 

I_coNer

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Sounds like the motherboard may be on it's way out. Have you tried shorting out the power button pins on the motherboard. Or there may be an issue with the PSU itself.

No I haven't tried that. I'll give it a shot. How do I do it correctly? If I take a wire and be sure each end touches one pin each on the pwr pins and let it touch for about 5-10 secs it should be the same effect as with the power button right?

Btw I just read that a lot of other people have had the same problem with boot as me - the system turns on but then it just stands there with fans on full and nothing else happens. Some fixed it with cmos clear (which I already tried) so I'm kind of blank here but I'm thinking it's probably the motherboard?
 

I_coNer

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Ill give it a shot.

Hmm, I can do it two ways right? One is to short the pwr pins on the motherboard, and another is to short the pins directly in the powersupply atx connector?

I read that you can manually short the pins in the atx connector on the power supply to get it to start (without being attached to a mobo) - aren't those pins the same as those on the mobo (just directly into the psu) - so if I short the pins in the atx connector for 5-10 seconds the power supply *should* turn off? What pins is it btw? Of course my pwr supply is atx 24 connector.
 

I_coNer

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Short circuiting the pwr pins yields the same result. I have to turn the computer off using the pwr button on the back of the power supply each time since I can't otherwise.

A weird thing is that when I turn on the pwr supply button my computer automatically starts? Normally I'd need to push the chassis pwr button (or short circut the pwr pins) before it turns on?

I tried unplugging my pwr supply completely from the motherboard and it just turns on by itself when I turn on the pwr button on the back even though it isn't short circuited in the atx connector?!
 

qwertycopter

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A weird thing is that when I turn on the pwr supply button my computer automatically starts? Normally I'd need to push the chassis pwr button (or short circut the pwr pins) before it turns on?
Sounds like your motherboard may be shorted somewhere. You could try rebuilding outside of the case (I know it's a pain).
 

I_coNer

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A weird thing is that when I turn on the pwr supply button my computer automatically starts? Normally I'd need to push the chassis pwr button (or short circut the pwr pins) before it turns on?
Sounds like your motherboard may be shorted somewhere. You could try rebuilding outside of the case (I know it's a pain).

I'm thinking more that my pwr supply is the cause? Since it turns on by itself, perhaps it's short circuited in dust inside? It's not normal for a pwr supply to turn on by itself when given power is it?