I've been having a frustrating issue where my PC shuts down around 30 minutes into playing games, specifically Roblox. It seems to happen faster when I have multiple applications running. I've checked with HWMonitor and confirmed that there aren't any overheating issues, even when stressing the CPU to max power using Cinebench. This shutdown only seems to occur during prolonged gaming sessions. I suspect it might be a power supply issue, as I faced a similar problem about a year ago and replacing the PSU resolved it. I'm curious why this issue has come back so soon after the initial fix. Here are my specs: AMD Ryzen 7 3700X, 16GB RAM, GeForce RTX 3060 Ti.
5 Answers
You might want to increase the fan speeds on your GPU while you're gaming. Sometimes they need a little extra help to keep cool during intense sessions.
Definitely check the fans on both your CPU and GPU. If they’re working fine, consider reapplying thermal paste on them.
Make sure to clean out your power supply vents. If the airflow is blocked, it can lead to overheating, triggering a shutdown for safety.
Have you thought about running some memory tests? Stress testing your RAM could give you some insight into whether it’s part of the problem. It’s worth a shot!
I've been through something similar before. You should check whether your power supply can handle your system. An upgrade could help, along with improving cooling by adding more fans.

I ran CPU and memory stress tests and they were totally fine, so that doesn't seem to be the issue.