PC Randomly switching off

Jetz7 · December 26, 2021

Hi all

The system specs are:

CPU: Ryzen 7 Pro 4750G (8c/16t) (brand new)

GPU: Asus TUF GTX1650 Super 4Gb (bought after 1 month of usage)

RAM: 32GB (4x8GB) Corsair Vengeance RGB Pro DDR4 3000MHz (brand new and MemTested)

PSU: SuperFlower Leadex II 550W 80+ Platinum (bought second hand but still under warranty)

NVME SSD: Adata Swordfish 1Tb (brand new)

SSD: Crucial MX750 (Ubuntu boot drive) (second hand from my old laptop, no bad sector count)

The System is a dual boot with Windows 10 pro and Ubuntu 20.04. Whenever I boot into Ubuntu the system seems stable, that being said I have not been on the Ubuntu boot for a quite a while, as it is only used for research.

The problem:

Recently my system has started switching off for no apparent reason at very random times, sometimes it can happen while booting into windows, sometimes while I start up Forza Horizon 5, or closing Forza Horizon 5, or even other games.

As I write this thread the PC has been switched on for two/three hours with no issues. Two days ago it was switched on for the entire day without an issue. Yesterday I was watching something and went for lunch, so it was basically idling, came back to it switched off.

Another anomaly, is that after it switched off, and I try to switch it on again and boot into windows, it will switch of while booting.

I have also noticed sometimes while navigating Steam, the mouse input will lag immensely for about 5 seconds and then resume normal smooth service.

It is at the point where I switch the power supply off at the back of the PC and even remove the cable for a few hours, and then it will boot up stable.

Fixes I have tried:

There are no apparent temperature issues either (as I have been able to game for hours on end), I gave it a clean recently, really not much dust at all. Cleaned the PSU also, using a compact blower on a low-ish setting.

I have checked the RAM, one stick once not seated properly, but is now seated.

I even tried DISM and sfc /scannow to "repair" the windows install, but no success.

Possible diagnosis I think but I am really not sure:

I am expecting my PSU is on its way out, but I not sure how to test this, Secondly, I have seen a ton of JayzTwoCents videos on troubleshooting, the issue did go away for a while after DDU-ing the GPU drivers, but then it returned.

Even after cleaning, the PC was stable for about two weeks (but it was switched on less during this period).

I also suspect the CMOS battery, but given I got the motherboard brand new in April, I doubt it.

There are Molex connectors open that can touch that case from the SATA cable going to the Ubuntu SSD, so I am not sure if I should just tape them up, but I feel it is more a software issue.

I really have no idea what the issue could be. I do have videos of it switching off as well, not sure if I can post those here or not.

Any help is greatly appreciated.