The tester will emit a loud, continuous beep if a voltage rail is missing or out of spec.
Why Your Power Supply Matters The Power Supply Unit (PSU) is the heart of your PC. It converts AC power from your wall into clean DC power for your components. A failing PSU causes crashes, random reboots, or permanent hardware damage. Checking your PSU helps isolate power issues from software bugs. Step 1: Analyze Software and System Symptoms how to check power supply on pc
If your PC boots into the startup screen, you can check voltages without using tools. The tester will emit a loud, continuous beep
The PC restarts instantly without showing a Windows Blue Screen (BSOD). A failing PSU causes crashes, random reboots, or
Bend a metal paperclip and insert one end into the green slot and the other into the black slot.
Unplug all power cables from your GPU, motherboard, and hard drives.
If you have gone through the steps above and are still unsure, the only definitive way to check a PSU is to swap it out.