This article explains how to manually test a power supply with a multimeter. The process is risky due to the voltages involved and is not for the average user. This information applies to a standard ATX power supply. Almost all modern consumer power supplies are ATX power supplies.
Manually test a (PSU) power supply with a Britec multimeter
Testing a power supply manually with a multimeter is one of two ways to test a power supply in a computer.
A properly performed PSU test with a multimeter should confirm whether the power supply is working properly or needs to be replaced.
Before you begin, read these important PC repair safety tips because of the dangers involved in the process. Manually testing a power supply requires working closely with high-voltage electricity.