You plug the 24-pin cable into the tester and turn the PSU on. The screen displays the voltage on the 3.3V, 5V, and 12V rails and usually beeps if everything is okay.
If your PC won't turn on at all, you might suspect the PSU is dead. The Paperclip Test bypasses the motherboard to force the PSU to turn on. how to check the power supply of my pc
Checking your PC's power supply (PSU) is a critical troubleshooting step if your system is crashing, failing to boot, or making strange noises. Unlike your CPU or GPU, the PSU is often a "silent" component that doesn't communicate directly with Windows, making it harder to diagnose via software alone. You plug the 24-pin cable into the tester
“Insert one end of the paperclip into the pin slot with the green wire, and the other into a black ground pin. Be careful not to touch anything metal.” The Paperclip Test bypasses the motherboard to force