Question PC randomly shutting down

Aug 14, 2022
Hi, recently i've been experiencing my pc just shutting down out of no where usually while gaming. Less demanding games like GTA and RDR2 work just fine even at max settings, however when I run higher demand games like star citizen for example, as soon as my character loads in, the pc shuts off as if someone unplugs it. No blue screens, or any kind of error messages, everything just stops and automatically turns on after a few seconds bringing me back to the windows sign in page. This also happens sometimes when I'm playing DCS in a big multiplayer server. I just build the pc a few months ago and everything was working perfectly then, but these issues just started to come up. My main suspicion is that there's something going on with the PSU because it's used, and I have no idea of it's previous condition, and this is the message that it gives in event viewer when it shuts down:

"The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

While gaming, the CPU+GPU temps almost never go above 70c so I'm almost certain that the shutdowns have nothing to do with overheating issues. Plus, the PSU is 850w and under max load the GPU usually takes 300w and CPU around 50w.

These are my pc specs, everything bought in new condition except for the PSU and its cables like I mentioned earlier. (I'm also running on windows 10 pro if it matters):

Well, it couldn't have been TOO old of a PC, since that model was only released in 2016 and it has the best warranty on the market at 12 years. Of course, that doesn't mean there can't be something wrong with it but if you are able to get the original purchase information from the person that gave it to you then if something IS wrong with it you could get it replaced for the cost of one way shipping.

Aside from that, that unit is like one of the absolute best models that exists and unless somebody caused it to be damaged I'd be really surprised if it was bad.

This shutting down instantly usually only happens if protections are triggered and that generally means something is shorting out or going out of spec. It could be the motherboard, the power supply or something else causing the protections on one of those two to kick in.

I'd pull the whole thing out of the case and test it on the bench. Look for things like a standoff in the wrong place under the motherboard, not lined up with any mounting hole, screws trapped in between, etc. Look for any kind of scratches or apparent heat damage, or anything that looks unusual on the motherboard. Testing the PSU would probably be a really good idea too. Check all wiring two or three times to make sure everything is FULLY seated and exactly where it belongs. Make sure memory is fully seated. These links should help.