Diagnosing random game freezes: how to tell PSU vs RAM vs motherboard.

[JerryGJ]

I've been troubleshooting a persistent issue with my custom-built PC where it randomly freezes during gaming, requiring a hard reboot, and I've exhausted the basic software fixes like driver updates and clean OS installs. I suspect a hardware problem, possibly with the power supply or RAM, but I don't have easy access to spare components for swapping. For those experienced with hardware diagnostics, what systematic process or specific software tools would you recommend to isolate the faulty component between the PSU, motherboard, and memory without a full bench of test parts, and are there any telltale signs in the system logs or behavior I should be looking for that point strongly to one over the others?