How to Test a Power Supply Using a Power Supply Tester
If you have some experience working on your computer and feel comfortable following instructions, this process should take about 30 minutes to complete. However, it may not be suitable for those who are new to computer maintenance. Before proceeding, be sure to read the safety tips. Once you have done so, you can begin the process.
Your PSU Is Good, But Your PC Won’t Start
Testing a power supply on a desktop computer using a power supply tester device is one of two ways to test one in a computer. There should be little doubt about whether your PSU is working properly after testing it with a PSU tester. To make the power supply test easier, move the disconnected and open case somewhere you can easily work with it, such as to a table or other flat, non-static surface. It’s not necessary to remove the actual power supply from the computer, nor should you need to disconnect any data cables or other cables not connected to the power supply. Depending on the PSU that you have, you might not have a 4-pin motherboard connector but instead a 6-pin or 8-pin variety. If you have more than one type, only plug in one at a time along with the 24-pin main power connector. You’re just looking at the LCD screen at this point, so don’t worry about any other lights or voltage indicators not located on the actual LCD readout. If all the reported voltages fall within tolerance, you’ve confirmed that your power supply is working properly. If you’d like to test the individual peripheral power connectors, continue testing. If not, skip to Step 14. Both of the motherboard power connectors that you connected to the tester earlier should remain plugged in throughout these tests of the other power connectors. Only the SATA power connector delivers +3.3 VDC. You can see the voltages delivered by the different power connectors by looking at the ATX Power Supply Pinout Tables. Repeat this process, beginning with Step 11, testing the voltages for the other power connectors. Only test one at a time, not counting the motherboard power connectors that stay connected to the tester the entire time. Assuming your power supply didn’t test as bad, or you’ve replaced it with a new one, you can now turn your computer back on and/or continue troubleshooting the problem you are having. However, there are several reasons a computer won’t start other than a malfunctioning power supply. See How to Fix a Computer That Won’t Turn On for a troubleshooting guide and more help with this problem.
