Question PC randomly shuts down (see details)

Jul 26, 2021
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Hello,

Any help or ideas would be appreciated!

Context: PC has been acting up. First issue was that it got stuck in a boot loop to BIOS because it didn't recognize the SSD boot drive. Fixed this by unplugging the SATA and plugging it back in. Seemed odd but whatever. Now, my PC keeps randomly shutting down and unspecific intervals.

Issue: PC keeps randomly shutting down and unspecified intervals. When it shuts down I have to turn the PSU off and on before it will boot back up.

Troubleshooting: I've reset the bios, and monitored the CPU and GPU temps which are normal. Fan profiles all seem fine but the two rear 120m fans keep sporadically ramping up and down, (these are two fans on one side of a push pull config for a radiator).

Specs:

  • CPU: Ryzen 5800x
  • GPU: EVGA FTW 3080ti
  • Mobo: ROG Strix B550-F
  • RAM: Trident Gskill 64gbs (four sticks), DDR4 cocked at 3600
  • HDD: 2x Seagate 2tb
  • SSD: Samsung EVO 500gn (boot drive)
  • M.2 NVME SSD: Crucial 1tb
  • PSU: EVGA Super Nova 850w G5
  • Fans: 9x Lianli AL120 Uni fans, 2x NZXT 120m
Note: All of the hardware is new except for the Seagate HDDs and Samsung SSD.
 
Last edited:

Aeacus

Champion
Ambassador
Random reboots or shutdowns are mostly caused by 2 issues:
  1. CPU/GPU overheats and to prevent any damage, system shuts down.
  2. PSU fails to deliver enough power to the GPU or fails to keep smooth enough voltage for PC's operation.
First check your CPU/GPU temps, both at idle and under load. If temps are within reason then it's safe to assume that it's the PSU who is acting up. If so, RMA your PSU.
 
Reactions: Secritsquirrel
Jul 26, 2021
13
1
10
0
Random reboots or shutdowns are mostly caused by 2 issues:
  1. CPU/GPU overheats and to prevent any damage, system shuts down.
  2. PSU fails to deliver enough power to the GPU or fails to keep smooth enough voltage for PC's operation.
First check your CPU/GPU temps, both at idle and under load. If temps are within reason then it's safe to assume that it's the PSU who is acting up. If so, RMA your PSU.
I assumed the same. The GPU and CPU temps seems stable, for context this has been happening while idling and not under load.

Thinking it might be the PSU, which is annoying because less then 6mo old.

NOTE: All my RGB settings also reset when this happens.
 

Aeacus

Champion
Ambassador
Thinking it might be the PSU, which is annoying because less then 6mo old.
There are lemons, even among the best. Hence why PSUs have warranty.

Another possible cause, would be your main electricity grid, that has brownouts or blackouts. Now, it doesn't need to be so long of a blackout that you can notice. PSU's hold-up time is between 17 to 30 milliseconds (ATX PSU standard defines it to be minimum of 17ms, while high-end units have it ~30ms). Now, 1000ms = 1 second. So, you can imagine how short of a time is 30ms. You won't even notice it.

An UPS will fix the main electricity grid issues, since it switches to battery power within 2-5 ms.

Though, if your PC shuts down often, too often to be considered as electricity grid issue, then it most likely is PSU issue. Still, IMO, every PC should be backed up by UPS.
(Both of my PCs are, one UPS per PC.)
 
Reactions: Secritsquirrel
Jul 26, 2021
13
1
10
0
There are lemons, even among the best. Hence why PSUs have warranty.

Another possible cause, would be your main electricity grid, that has brownouts or blackouts. Now, it doesn't need to be so long of a blackout that you can notice. PSU's hold-up time is between 17 to 30 milliseconds (ATX PSU standard defines it to be minimum of 17ms, while high-end units have it ~30ms). Now, 1000ms = 1 second. So, you can imagine how short of a time is 30ms. You won't even notice it.

An UPS will fix the main electricity grid issues, since it switches to battery power within 2-5 ms.

Though, if your PC shuts down often, too often to be considered as electricity grid issue, then it most likely is PSU issue. Still, IMO, every PC should be backed up by UPS.
(Both of my PCs are, one UPS per PC.)
So this is odd. When I originally had boot issues I pulled the side panel off to unplug/replug the SATA on the SSD. Which fixed the boot issue.

And after that is when I started having the random shut downs. For fun, I pulled the side panel off and let it run and it didn't shut down after hours of testing. I think the side panel was putting pressure on something that it wasn't before so I shuffled the cables around and it's fine. now. Go figure.
 
Reactions: Aeacus

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