If you are working as a PC Tech and need to test a power supply, there is a makeshift way to do it. You will often encounter situations in which the power supply is potentially faulty. One way to test if the power supply has totally failed or not is a simple field power supply test that requires only a paperclip. Unplug the motherboard connector and make sure the power supply is connected to the wall. Then, bend the paperclip and use it to connect the green connector on the motherboard’s 20-pin connector to any black connector on that same connector. The power supply, if working correctly, should start. Otherwise, the power supply is likely to be faulty.