Help, My PC is shutting off randomly (power just seems to cut out). It wroked fine for several years without issue. I haven't changed any hardware or software in several months.

What's I've tried:

CPU temps are very good when it shuts off (under 40 C). So, it's not overheating. Heat sink and PC are clean and dust-free.

The power supply is good (still happens with a new power supply)

All cable connections are secure.

Memory is good (I ran Memtest86 for half a day and got zero errors)

Memory voltage is good (1.536 v)

I updated the bios - still happens

I downgraded the bios - still happens

It happens in Linux, Windows XP, and Windows 7 (so, it's not an OS or software issue). Even still, all power management settings are disabled in all operating systems.

It also happens regardless of which hard drive I use.

House's power is good (everything else stays on).

The outlet is good (other pcs work fine on the same outlet). Other items also stay on when the pc shuts off (like the monitor).

Motherboard is not bowed. The motherboard and case were designed so the case supports the weight of the heat sink.

So far it hasn't shut off if I stay in a pre-boot environment like the bios or when running memtest86 (at least, it hasn't yet).

So, what now?

Let's assume for the moment that the motherboard and cpu aren't failing. What else can cause the computer to randomly shut off?

edit:
One thing I've noticed is that if I leave the computer running with an OS booted, but not doing anything, it can go several hours and doesn't shut off (yet). It only seems to happen while I'm doing something. However, I can often work actively or play a game for several hours and it won't shut off. It seems completely random.

edit 2:

Also, it's not malware. I use linux to avoid that and I keep windows offline always. I only install programs in windows that's I've downloaded in linux that also pass a complete scan from the virustotal website.

Have you checked your computer admin logs?

Very likely your computer is crashing ... just not getting a "blue screen"
So look for error logs about time computer shuts down.

If it was something overheating you couldn't just turn the computer back on.
You would need to let it "sit" and cool off for a while before you could start it up again.

So is the computer just booting up right after shut off fine?

I had something similar happen before was graphic driver
crashing every so often.

Like I said, it happens in every OS, windows xp, windows 7, and linux. The graphics drivers have been working fine since last year. However, I also tried reinstalling them to no effect.

I have no clue how to check computer admin logs.

It's not a regular crash / freeze, the power cuts off instantly like it would if the plug was pulled. One second I'm working and them BAM, it's off.

The computer either just shuts off and stays off, or it reboots (with the new power supply it sometimes reboots).

When I restart the OS, it mentions it has to correct errors due to an unexpected shut down, etc (linux says it's cleaning up orphaned files).

there is thing called google try
"windows check admin crash log" There is link in quote have to abuse crappy forum software to post it cause of rep trolls

Can't post links with negative rep...

Graphic driver was just example of something that could crash.

At this point, I'd say it can be only the mobo\cpu O_o

(ah, but did you try using another GPU?)


P.S: btw, my Skylake seems to have problems resuming after sleep. Did you check that?

It says to run the Event Viewer. I did that, but I'm not sure what that's supposed to tell me. I saw some errors, but they dont' make any sense.

Like I said, it's not a problem with Windows. It happens exactly the same way in every OS. I mostly use Linux and Windows XP. It just also happens in Windows 7.

from what you listed it can only be a mobo or cpu issue really

I don't have another video card. I could try using the onboard video though.

All power management systems are turned off. My computer doesn't go to sleep, hibernate, etc. The issue happens only when actively using the comptuer, but completely randomly.

Give it a go.
I don't know it it would be better to also detach the dedicated GPU for a better test.

It could also very well be the power supply. Faulty power supplies can cause all kinds of weird issues.

he said he had a new one though
but my first instict was to say shoddy psu

My money is on either a bad connection with you heatsink to your CPU, or a bad voltage going into your RAM. Both have caused this for me in the past (in the RAM case it was because it reset to factory settings, and needed more than 1.5v).

Oh, you are right, I totally missed that he has tried with a new PSU. The a faulty mainboard would be my guess as well.

I couldn't figure out what could be the issue, but holy shit, nice diagnosis. That had to take a while to get to.

It's a long shot, but the processor might be somehow damaged. (I meant like a loose wire or anything that might affect the processor when it starts to draw power)

Maybe your new power supply is faulty as well. Can't rule that one out. I know I had this problem with mine until I replaced it with a good one. What was your previous model and what is your new one? I thought my Corsair HX750 Silver was solid but it was the culprit giving me random outages all of that time.

Linux has malware by the way. So does android. Anything that uses a browser is a vulnerability and you're not as safe as you think.