PC randomly shuts down and I can't think of a reason.

[KuronoXD]

As the title says, my PC has been randomly shutting down instantly while ALL the fans go into hyper speed (case fans, CPU and GPU as well). I don't think it has to do with temps, as I have pretty good circulation with 7 case fans (and I keep the AC running the whole day).

And explaining the "random" part of the title, it seems to have some consistency but no logic that I've figured out; it happens when I'm just browsing, while I'm listening to music or watching a video in MPC-HC and most consistently when I'm watching videos in youtube, but it has never happened while I'm gaming.

I have already stress tested most components but they didn't fail or throw an error (CPU, RAM, and GPU) and crystaldisk still shows me good SSD integrity (92%), so I have no logs to speak of as to what could be failing (I don't get a BSOD, just computer off and spinning fans).

 

The only other components are the PSU and Mobo, but I have no reliable way to test those, any ideas?

[PopsicleHustler]

It could be your motherboard going bad.

[AT0MAC]

Not long ago a friend of mines PC was going on and off totally random, i went to do the big inspection and found out a tiny drop of thermal paste had gone down the side and was touching 2 pins on his cpu.

As the paste was arctic silver it is electrically conductive, so cleaned it off and swapped it for a smaller amount of a non conductive paste, just to be sure.

Maybe you have the same issue.

[SenKa]

Maybe your GPU is dying? That's always been the cause when I had that issue 

[darknightbacca]

Use the beep code method with the Motherboard to see if anything comes up, + pc randomly shutting down is a symptom of a dying motherboard (look for any visual damage, blown capacitors, damaged circuitry) 

 

As for power supply try all testing methods,  you can find them online + take out your gpu and just watch some youtube and see if it crashes still.

[KuronoXD]

If anyone likes the feeling of closure on threads about troubleshooting, I finally figured out what's wrong (...I think). Special thanks to @SenpaiKaplan, who poinited me in the right direction.

It actually does have to do with the GPU, but not because of it going bad, but that it sucked so much juice that my old PSU failed on sustained, specific loads.

To ensure that it wasn't actually my graphics card, I set the Power Limit at 90% and the unexplained shutdowns stopped ever since. Today, I tried playing in 4K with almost everything maxed out and set the power limit back to normal (120% when gaming, for overclocking); some minutes in I experienced the instant shutdown.

So, I decided to put the limit at 95% and it was a while before something went wrong, but this time the PC rebooted on its own and after post, my ASUS mobo had the message "A PSU power surge has been detected during the previous power on. ASUS Anti-surge was triggered...".

 

It seems then, that my PSU fails at high sustained loads or something is specifically wrong with the 12V rail, and that when the GPU is set over 100% it is too much too fast and everything fails instantly without leaving an explanation, but under 100% it leaves time or capacity for the mobo to handle the fail-and-reboot process. 

[BuzzLookAnAlien]

26 minutes ago, KuronoXD said:

If anyone likes the feeling of closure on threads about troubleshooting, I finally figured out what's wrong (...I think). Special thanks to @SenpaiKaplan, who poinited me in the right direction.

It actually does have to do with the GPU, but not because of it going bad, but that it sucked so much juice that my old PSU failed on sustained, specific loads.

To ensure that it wasn't actually my graphics card, I set the Power Limit at 90% and the unexplained shutdowns stopped ever since. Today, I tried playing in 4K with almost everything maxed out and set the power limit back to normal (120% when gaming, for overclocking); some minutes in I experienced the instant shutdown.

So, I decided to put the limit at 95% and it was a while before something went wrong, but this time the PC rebooted on its own and after post, my ASUS mobo had the message "A PSU power surge has been detected during the previous power on. ASUS Anti-surge was triggered...".

 

It seems then, that my PSU fails at high sustained loads or something is specifically wrong with the 12V rail, and that when the GPU is set over 100% it is too much too fast and everything fails instantly without leaving an explanation, but under 100% it leaves time or capacity for the mobo to handle the fail-and-reboot process. 

Hurray OwO

 

Are you gonna get a new PSU?

[SenKa]

13 hours ago, KuronoXD said:

If anyone likes the feeling of closure on threads about troubleshooting, I finally figured out what's wrong (...I think). Special thanks to @SenpaiKaplan, who poinited me in the right direction.

It actually does have to do with the GPU, but not because of it going bad, but that it sucked so much juice that my old PSU failed on sustained, specific loads.

To ensure that it wasn't actually my graphics card, I set the Power Limit at 90% and the unexplained shutdowns stopped ever since. Today, I tried playing in 4K with almost everything maxed out and set the power limit back to normal (120% when gaming, for overclocking); some minutes in I experienced the instant shutdown.

So, I decided to put the limit at 95% and it was a while before something went wrong, but this time the PC rebooted on its own and after post, my ASUS mobo had the message "A PSU power surge has been detected during the previous power on. ASUS Anti-surge was triggered...".

 

It seems then, that my PSU fails at high sustained loads or something is specifically wrong with the 12V rail, and that when the GPU is set over 100% it is too much too fast and everything fails instantly without leaving an explanation, but under 100% it leaves time or capacity for the mobo to handle the fail-and-reboot process. 

I figured it was something to do with the GPU! Im glad it's all fixed now though, best of luck with your system stability in the future!