I'm having a serious problem with my PC that keeps shutting down randomly, even when it's just sitting idle. Restarting it is a hassle because I often have to press the power button multiple times and flip the main plug on and off before it will start up again. I initially thought it was a problem with the power supply or motherboard, so I upgraded my PSU from a Corsair Cv650 to a Cx650 and replaced my old motherboard (Gigabyte B550M DS3H) with an MSI B550M Pro VDH WiFi. I'm also trying out a friend's CPU, which is the R5 5600G, to see if my R5 5600 is at fault. Despite these changes, the random shutdowns continue, occurring while browsing, gaming, or editing. I've been keeping an eye on the temps, and they're fine—nothing goes above 70 degrees even when gaming. I recently reapplied thermal paste, and I haven't overclocked or undervolted my system. I've checked the RAM too, using just one stick, but it still shuts down. My setup includes an RX6600 GPU, 16GB of RAM, and a 1TB SSD. Taking my PC to a shop would mean being without it for at least 30 days because of warranty policies, which I can't afford due to my time-sensitive work. I'm at my wit's end trying to figure out what's wrong; if anyone has suggestions or needs more details, like my event viewer readouts, I'm all ears!
2 Answers
Make sure to check your event viewer for any critical failures. Ignore the other warnings or errors and focus on those critical ones. They can often provide clues as to what's causing the shutdowns. If it usually says the last shutdown was unexpected, that could hint at a deeper issue, so pinpointing those messages might help narrow things down.
It sounds like you've done quite a bit already, but I would consider checking the wall outlet or power strip you're using. Sometimes, the issue might not be with the PC itself but the source of power. Ensure that everything is properly connected and check if the plug or strip is on a switch that might be getting flipped unintentionally. There could also be a loose connection or an issue with the circuit breaker if you’re sharing it with heavy appliances that might be tripping it.

I checked the event viewer and saw that it says the last shutdown was unexpected. Sometimes it even restarts right after shutting down, which is really frustrating. I’ll keep an eye on those details.