Random Shut Downs... Why!?!?

Afternoon,

I was told by Baloo?! some of you guys on here might be able to shed some light on this issue I'm having..

For the past 3-4 days my pc has been randomly shutting down, could be at idle or under load it doesn't seem to be picky...
I've checked the error logs and nothing, I've switched off automatic shut down on error to try and get more of a diagnostic but it doesn't even go to the bsod before it dies.
I recently replaced my old 750watt psu with a xfx pro series 850w supply, that was 2 months ago and I've had no problems since untill now. I've also checked and rechecked connections, I'm sure overheating is not the problem...

Anyone any idea what else could be causing this? Or what to check next?

Cheers for any help!

I will post system specs and speedfan results once I get home if that helps any.

My system:

Intel® Core™2 Duo E6850 (2 X 3.00GHz) 1333MHz FSB/4MB L2 Cache
4GB CORSAIR XMS2 800MHz
ASUS® P5N32-E SLI+: Quad-core CPU Ready, NVIDIA® Dual X16 SLI
64 BIT WINDOWS® VISTA Home Premium
400GB SERIAL ATA II HARD DRIVE
768MB GEFORCE 8800GTX PCI Express
ASUS SILENT KNIGHT II PURE COPPER ULTRA COOLER
800W Quiet Quad Rail PSU (replaced 2 months ago with 850w XFX Proseries)

When you say "shut down", do you mean as though the power has been cut off (i.e. fans spin down, lights go off etc)?

Whats the spec of your pc?

Yeah, everything shuts down, fans power off... No warnings, just cuts out completely..

It doesn't reboot automatically but will start up with no problem if you power it back on..

Maybe a dodgy connection somewhere, try taking out the motherboard power cables and putting them back in, or the PSU has a problem.

I think what Saundie means, does it actually 'shutdown'? Does the windows 'Shutting Down...' thing come up or does the power just go off instantly?

I think what Saundie means, does it actually 'shutdown'? Does the windows 'Shutting Down...' thing come up or does the power just go off instantly?

apologies, when I say "shut down" its not a shut down per se, it's as though the power has been cut off, it seems to just lose juice....

Mmm OK, if it suddenly does it without warning beeps or the fans going crazy then I'll take a guess that it's either not a temperature problem, or if it is whatever is getting too hot is on the way out as usually when say a GPU gets within a certain % of its max temp all the fans will run flat out and it will sound like its trying to take off Get GPU ID or something running to monitor the temp of your card and maybe realtemp or soemthing just so you know what your CPU is doing.

The fact that it doesn't auto-reboot when it dies makes me want to say it's mobo or component related, sorry can't be of more help but to go any further I'd really need to be sat in front of it with a scope.

It might be worth a complete re-build, disconnect everything then blow out the connectors with air and inspect as you re-assemble. Failing that it's a train ticket to Cardiff and the cost of a kebab

Thanks for the replies guys.

I had another look last night and noticed that the thermal paste between the CPU and fan is completely gone...

I rand speedfan and got the CPU temp showing as high as 102c... I assume this is well beyond what is should be?

Time to clean up an reapply the thermal I reckon? Certainly won't hurt..

102°C is well into danger territory for any CPU, the max guaranteed operating temp for your CPU is quoted as 72°C, so yeah, I think you've found your problem

Clean both heat sink and CPU (not with water! hehe just wipe them clean) then re-apply thermal paste, not too thick, just enough to cover the CPU.

edit - in fact I'm impressed that an Intel part has survived that temperature for as long as this has been happening, I'd be surprised to see that chip last as long as it would of done before, you might of got lucky but only time will tell. You may also need to investigate exactly what happened to your heat sink compound so that it doesn't just happen again, what type are you using?