Need help with possible cause, computer reboot itself.

[apvm]

Computer reboot itself like someone hitted the reset key or pulled the power plug, randomly, even when idle, happen about 1-2 times per week...computer on 24/7 According to Windows 7 log the Critical error is kernel power related. This started to happen early December but computer was working fine for more than a year.

Power supply is a Enhance 500w... suppose to be a very good PSU

Anyway did test memory with memtest overnight no problem and everything is at stock no overclocking, memory is underclock to run at 1333 DDR3

Computer is

Windows 7 64bit
Athlon II X4 620
Gigabyte MA790XT-UD4P
Adata 2x2GB 1600 DDR3
ATI HD 3650 fanless video card
2x ide DVD burner
1x Sata DVD burner
5x Sata HDD
1x Intel PCI NIC
1X PCI SCSI card controlling a scanner.

Possible cause?

By the way I know software monitor is not very accurate but according to CPUID HWmonitor my -12v rail is at around -9v anyway I don't think this is the cause since AMD overdrive reported it at -12.04v

[Shadowmeph]

I would check for heat. I know of one virus a few years back that would make your pc reboot if you where connected to the internet, so unplug your pc from the net to see if it is that virus ( if it is a virus at all). Then I would do a full virus scan in safe mode to see if there is any virus's.

[apvm]

Originally Posted by Shadowmeph

I would check for heat. I know of one virus a few years back that would make your pc reboot if you where connected to the internet, so unplug your pc from the net to see if it is that virus ( if it is a virus at all). Then I would do a full virus scan in safe mode to see if there is any virus's.

Not heat since CPUID hardware monitor report cpu at 28c, actually, the computer was either idle or doing very little when this happen. Also done virus and Melware scan...nothing. Thanks.

[Shadowmeph]

do you do any changes to your system before this started to happen?
did you disconnect from the internet?

another thing you could try is to shut down the pc unplug the power cord and then press the power button ( this will drain the remaining power in the PSU) then plug the power cord back into the psu and fire up the pc .

[apvm]

Originally Posted by Shadowmeph

do you do any changes to your system before this started to happen?
did you disconnect from the internet?

Nothing at all...this only happen about once a week so disconnect from the internet to wait for the reboot is not really an option and to be honest I don't think this is virus relayed...it is not like a reboot, like someone pulled the plug for a second,,,everytime this happen..Windows 7 would ask me if I want to boot normally...unlike a normal reboot which 7 will not ask.

[Soultribunal]

My first gut instinct would be a Failing board.

I had this happen almost similar circumstances on an old 780G board and it was the board itself that was dying.

ST

[apvm]

Originally Posted by Soultribunal

My first gut instinct would be a Failing board.

I had this happen almost similar circumstances on an old 780G board and it was the board itself that was dying.

ST

I am thinking this as well but is there a way to be sure. Wish AM3+ board is available now. Thanks.

[Soultribunal]

Originally Posted by apvm

I am thinking this as well but is there a way to be sure. Wish AM3+ board is available now. Thanks.

For me there was nothing consistent , which is what helped me come to that conclusion. Best bet is to see if you can find someone with an AM3 board and do a swap. Thats what solidified it for me.

ST

[apvm]

After a week of trouble shooting....it may be the case's reset switch connection....the connection was plug onto the motherboard pin with + and - reversed....most of the time it does not matter but a few of the reboot happen when I move the headphone plug or trying to plug a USB Flash drive onto the case's front USB, I usually get a reboot/restart once a week....corrected the above for 2 days now, waiting to see if this was the cause...fingers crossed.

[KaptCrunch]

I'd check all usb connections and sockets, the bottom side of MB for shorts and also a faulty start button