PC powers down and reboots

I built a new PC late last year and it has run fine till now. (spec as listed in my setup at the side)
Then this morning, was checking email when it powered down, the blue power light went out on the case and it went silent (though screen and everything else in the room remained powered up).
Five seconds later, it powered up again and rebooted itself without me doing anything.
I checked that the power line was plugged properly into the PSU at the back and it seemed to be.

It went past the BIOS screen, asked whether to start windows normally or not (I said normally), carried on for ten or so seconds and powered down.
Five seconds later, it repeated the process.

Powered down and rebooted itself four times,
I took the side off the case with a view to seeing what was going on - not that I know what to look for.
Anyway, it hasn't done it in the half hour since, with the side still off the case - I don't know if that's coincidence or relevant.
I was particularly baffled that it went dead, then rebooted itself five seconds later without me doing anything

Can anyone suggest where to start looking or how to rectify whatever it is pse?
I don't have any spare bits to swap in, and know very little about the workings.

can you go into the BIOS and give us the CPU temp and the voltages?

Will have a look and see Killie

meanwhile, I;ve just discovered there's an event log, and here's a screenshot of some of what's in mine
http://www.upload3r.com/serve/310111/1296463943.jpg

The gigabyte utility gives the following:
CPU 0.848V
DRAM 1.536V
+3.3v 3.360V
+5v 4.999V
+12v 12.302v

System 38 degrees
CPU 26 degrees

Kernal-power event id 41 seems to be the shutdown, heres what MS have to say about it.

http://support.microsoft.com/kb/2028504

random restarts like this could be a huge number of things hardware and software, some real testing is needed ideally.
best place to start is have u installed any new drivers or software in the short time before it started happening.
running memtest will help eliminate your ram to.

just noticed your cpu v looks a bit low too but im not sure on that.
if i remember rightly an Intel i5 760 should be around 1.1v can anyone confirm this?

I don't think Corsair make any XMS3 modules that run at less than 1.6v, tho I could be wrong. Your 1.536v would therefore be too low. The bios will often set a voltage lower than required.

Exact model number of memory would be helpful.

Quote:

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Originally Posted by sadbuttrue

I don't think Corsair make any XMS3 modules that run at less than 1.6v, tho I could be wrong. Your 1.536v would therefore be too low. The bios will often set a voltage lower than required.

Exact model number of memory would be helpful.

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hi sadbuttrue

The memory is here http://www.scan.co.uk/products/8gb%2...connector-160v

and it does say 1.6v, though it claimed to be compatible with my other stuff.

Is that likely to be the cause of the problem - and can I do anything about it?

Quote:

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Originally Posted by Cryptik

just noticed your cpu v looks a bit low too but im not sure on that.
if i remember rightly an Intel i5 760 should be around 1.1v can anyone confirm this?

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Hi cryptic, thanks for the reply. The spec says .6500V-1.400V for the CPU voltage, so I'd guess that's OK.

I checked out yr link on the event 41, and since it returned a code of zero, could well indicate hardware or drivers it seems.
I wonder if that could include the memory voltage ?

Would be easy enough to revert to a C: copy of a couple of months ago to rule out software/drivers, though I;ve not installed anything recently.

the voltage range is what is safe to run the cpu at, but running at the wrong voltage can cause varying degrees of instability and result in crashes same with ram voltage.

The memory is compatible, but you will need to set the voltage manually. It's easy enough to find in the bios.

Thanks guys, I've found how to change it so I'll do that and see if it happens again .
Odd that it's waited three months to show up as a problem though.

much obliged to you :)

If it stopped rebooting when the side panel was taken off then it must be a temperature issue (most likely on the graphics card, it being passive)... or a short in the case I suppose, though that's massively unlikely.