If you suspect that your computer’s power supply is not functioning correctly, you can use a multimeter to test it. A multimeter is a device that can measure voltage, current, and resistance. It is an essential tool for troubleshooting and repairs in electrical and electronic systems.

Here are the steps on how to manually test a power supply with a multimeter:

Step 1: Turn off the power supply and disconnect the power cable from the computer. The power supply should be unplugged from the wall socket, and no components should be connected to it.

Step 2: Open up the power supply case by removing all the screws holding the top cover in place. Every power supply case is different, but most cases have 4 to 8 screws holding the top cover in place.

Step 3: Locate the 24-pin motherboard connector on your power supply. It is the largest rectangular connector on the power supply. Pull the connector out of the power supply.

Step 4: Set your multimeter to measure DC voltage, and connect the black probe to a black ground wire on the 24-pin motherboard connector. The ground wire is usually black, and there are several of them on the motherboard connector.

Step 5: Touch the red probe to the first red wire on the 24-pin connector. The voltage should read +5V. Repeat this process for the other colored wires on the connector. The voltage should be as follows:

– Yellow: +12V

– Orange: +3.3V

– Red: +5V

– Blue: -12V

– Purple: +5V (standby voltage)

Step 6: Check the voltage on the 4-pin connector that powers the CPU. It is usually located near the top of the motherboard. The voltage should read +12V.

Step 7: Reconnect the 24-pin motherboard connector to the power supply and start the computer. Check the voltage on the 4-pin connector with the computer running. The voltage should read around 12V.

Step 8: Use the multimeter to check the voltage on the hard drive power connector. Touch the black probe to a black wire on the connector and the red probe to a yellow wire on the connector. The voltage should read +12V.

Step 9: Check the voltage on the 4-pin Molex connector. Touch the black probe to a black wire on the connector and the red probe to a yellow wire on the connector. The voltage should read +12V.

Step 10: Turn off the computer and unplug it from the wall socket. Reassemble the power supply case and connect it back to the computer.

Testing the power supply with a multimeter can help you determine if it needs to be replaced. If you do not feel comfortable performing these tests yourself, it is best to have a professional technician do it for you. Always be careful when working with electrical components and make sure to follow safety procedures.