Originally Posted by SGMRock
I agree with a few others on here, I would bet its the PSU or a power issue on the motherboard. I had similar issue with a system a while back and first thing I did was pull out an older spare reliable PSU I keep for troubleshooting and stick it in the system, after that zero issues so got the bad PSU RMA'd. (Good PSU's typically have long warranties of 7-10 years, so yours might even still be under warranty.)
Originally Posted by elemity
Hey, just wanted to say I had a very similar issue recently. PC would shut off completely when playing Assassins Creed Odyssey. Sometimes I could play for a couple hours before it happened other times I could only play like 10-15 minutes. It seemed random. Then it started doing it when playing other games that I never had an issue with in the past, like Destiny 2 and Path of Exile.
I had already planned on upgrading some of my hardware so I did the following over a week or two:
First I upgraded my ram. PC still shut off mid game.
Then I upgraded my CPU cooler. This also didn't fix the problem (though my pc did run a lot cooler!).
And finally I upgraded my PSU. I believe this fixed it because I have not had an issue since. (I upgraded this about 3-4 weeks ago)
So as a few others have already stated, its most likely your PSU. I would try that first if your planning on buying new hardware.
Wish I had a spare PSU, think I'm still gonna wait a few weeks to see if it shuts off frequently or not still, not sure how many of the problems I was facing were remedied by the clean install and driver updates, if it happens really rarely I can handle that but it was shutting off a lot (like a few times per day sometimes and several per week). It feels like most of the problems were solved so I am not sure how big of a problem it is atm or how many of the problems have been resolved or minimized.
I also need to make sure I check the power cables (modular power supply may have lose bits over a few years since I airdust and move my PC outside everytime I do it), and then try it. I also need to double check the wires run to the correct parts, cpu to cpu etc (dont know if connectors make it impossible to screw this up, pretty sure thats the case).
If I wasnt so lazy about tedious computer stuff I would do another clean install too lol, it froze and I had to force shutdown a few times and now windows update keeps failing even on manual install of patches VERY ANNOYING!