PC constantly turns itself off and restarts

[Pagi]

My PC constantly turns itself off and restarts, it usually stays on and running fine for a max of 5-10 minutes then just switches itself off and restarts. Actually not sure it restarts anymore, as just turned off now and did the last few times.
Went to turn it back on and power button doing nothing, that happens sometimes but then try again a few times or later and it works again…Actually 5 minutes after turning itself off and power button doing nothing it’s suddenly just turned itself back on.

I thought it was the CPU fan, so I cleaned up the fan and put new thermal paste down. No luck.
The CPU fan has some loose lock in pins but it seems pretty much locked and tight to the cpu.
Oh and I thought maybe it’s the Power supply plug connection or plug end being loose fit, as the pc doesn’t always turn on when I press the power button, but jiggling the PSU plug in connection just now didn’t turn the power off so guess maybe not that

Any ideas of what to try next to fix it?

[jmarket]

Hi there @Pagi and welcome to PCHF

Can you give us more information about the PC, such as motherboard info, CPU, RAM, HD, Graphics card, peripherals, etc?

Do you hear any beeps from the onboard speaker? Usually if it terminates itself after X minutes it usually indicates overheating

[georgeks]

“…just switches itself off and restarts.”

This can have different causes, can you also provide us with an estimate of your computer skills?
This will assist in suggesting a course of action.

Also: Do you have access to a different PC at home?

[TwitchisMental]

Have you tried using something like HWMonitor to watch the temperatures as the computer continues to run? As jmarket has suggested, this sounds like a classic case of overheating.

You can also check to make sure everything is getting the correct power via HWMonitor aswell.

[Pagi]

“…just switches itself off and restarts.”

This can have different causes, can you also provide us with an estimate of your computer skills?
This will assist in suggesting a course of action.

Also: Do you have access to a different PC at home?

Yeah i have a laptop and mac. My skills are decent, built my own pc and know bits and pieces. I

[Pagi]

Hi there @Pagi and welcome to PCHF

Can you give us more information about the PC, such as motherboard info, CPU, RAM, HD, Graphics card, peripherals, etc?

Do you hear any beeps from the onboard speaker? Usually if it terminates itself after X minutes it usually indicates overheating

No beeps, I assume I should hear beeps even though I have no speakers plugged in?

OS: Windows 7 Home 64BIT
RAM 4GB
Processor: INTEL CORE i3 2100 CPU 3.10ghz (x 4)
Graphics Card: NVIDIA GEFORCE GTX 460
Motherboard: ASROCK H61 PRO BTC
PSU: COOLERMASTER 600W
Hard Drive: SAMSUNG HM321HI SCSI

[plodr]

I assume I should hear beeps even though I have no speakers plugged in?
Not really. Old computers had a tiny built in speaker. Newer ones don’t.

[georgeks]

I hate it when I see it.
I still have a few left in stock, so when I build a new PC I add m/b speaker.

Most likely this is the result of users having no knowledge of what to do nowadays…

[veeg]

Any updates for us?

[veeg]

Any updates for us? After 48 hrs this thread will be closed.