Sometimes, you face some troubles while turning on your computer. It can be for various reasons. But, sometimes this issue occurs for the poor connection of the power supply. So, when you face an issue like Motherboard is not powered up, etc, you have to check if the power supply unit(PSU) is working properly or not. There are some methods below to test the power supply unit of your PC.
Table of Contents
How to Test the Power Supply
We will discuss several methods regarding how to test the power supply issue which can damage your computer badly.
Test if it Powers On
Step 1: First, you have to shut down your computer. You have to click on the Start menu and select the shutdown option from the menu. Once you shut down your PC, you have to unplug your computer from the outlet.
Step 2: Then, you have to open your computer case. Inside the case, you will find all the components of your PC like the Motherboard, the CPU, the GPU, etc, you have to disconnect all the power supply cables connected to the components. You have to unplug each power connection from the components. When you are unplugging the components, you have to note down the path so that you can plug in the components again and not damage anything because a simple mistake can damage your motherboard and CPU because of the damaged heat sink.
Step 3: Now, you have to make a paper clip tester. You have to straighten the paperclip and you have to bend it into the shape of U.
Step 4: When you insert the paperclip into the power supply, it will give the Power ON signal.
Step 5: Next, you have to find the 20 or 24 number pin connector. These pins are normally connected to your computer’s motherboard. These pins are the largest at5tached connector for the power supply.
Step 6: You have to find the green pin and a black pin there. These pins are PIN 15 & PIN 16. You have to insert the ends of the paperclip into the green pin and the black pin. There will be only one green pin, the number of the green pin is 15 and you will find the black pic next to the green. You have to make sure that the power supply is properly disconnected from the outlet.
Step 7: When you have inserted the paperclip into both pins, you have to place the cable in a place where it will be safe. Then, you have to plug in the power supply again to the outlet. You also have to turn on the switchback of the case.
Step 8: Now, when the power is on, you have to check the fan. You will hear a sound if the fan is moving. If the fan moves, the power supply is ok. If the fan doesn’t move, you have to double-check the pin connection. For this, you have to unplug the connections again.
Step 9: If the power supply doesn’t work, it is probably dead. With this process, you will know if the power supply of your computer is proper or not.
Test the Output
Step 1: You have to check the output with the help of the software. If your computer is functioning well and it can load any operating system, then you can check the power supply through any software. SpeedFan is software for this purpose. This software is for free and it will observe your computer’s operation and report the temperatures and voltage. You have to check the reports and make sure that it is under the tolerances. It is like stress testing your CPU and GPU. You can check this article to more about the CPU and GPU of the computer system.
Step 2: If this program can’t run on your computer, you have to do this manually. For this, you have to shut down the computer. You also have to unplug the power supply from the outlet and disconnect all the components from the power supply.
Step 3: Now, you have to test the power supply with a power testing unit. You can easily get it online or at any computer store at a reasonable price.
Step 4: Then, you have to find pins 20 and 24 on the power supply. You have to connect the power testing unit to these 20 & 24 number pins. After connecting the pins, you have to plug in the power supply again to the outlet. When the power supply connection is on, the tester will light up. Some tester needs to turn on the switch on it to active.
Step 5: Next, you have to check the voltages. You have to check four measurements of the 20 and 24 pin connectors. These following measurements you have to look for:
- +3.3 VDC
- +5 VDC
- +12 VDC
- -12 VDC
Step 6: You have to make sure that the first three voltages are within +/-5% and the fourth voltage within +/-10%. If you find any of these voltages outside of the tolerance range, you have to replace the voltage.
Step 7: You have to test the other connectors. If the main power cable is outputting the power properly, then you have to test the other cable like testing ethernet cable, or coax cable, etc one by one and test it. You have to unplug the power supply after every test.
Test with a Multimeter
Step 1: First, you have to open your computer’s case. You have to plug out the main power cable. You also have to disconnect all the cables outside of the computer.
Step 2: You can use a table or a flat surface to disconnect all the cables from the computer. You have to disconnect all the inside cables from each internal device. You have to remove the actual power supply unit from the computer. You have to group all of the power cables to test the power supply easily.
Step 3: When you assemble the power cables, you should reroute the cables and pull them away from the computer case. It will be helpful for you to test the power supply.
Step 4: You have to short out PIN 15 and PIN 16. You can use a piece of wire to short them out. You may have to look at the ATX 24-pin 12V power to check the locations of the pins. You have to make sure that the power supply voltage switch is appropriate for your country. For example: In the US, the voltage has to be set to 110V/115V. You can follow the Foreign Outlet Guide for the different voltage settings for other countries.
Step 5: Now, you have to plug the PSU into a live outlet. You also have to flip the power supply switch. After doing this, you may hear to sound that the fan is moving. If you don’t find any power supply switch, the fan should run automatically as soon as you plug it into PSU.
Step 6: Then, you have to turn on your multimeter and turn the dial to the DC voltage. If there is no auto range system, you should have to set the range to 10 volts. You have to test PIN 24.
Step 7: There are two probs with the multimeter. You have to take the black negative probe and connect it to the ground. Then, you have to take the red positive probe and connect it to the power line that you want to test. The PIN 24 main power connector has +3.3 VDC, +5 VDC, -5 VDC (optional), +12 VDC, and -12 VDC lines across multiple pins. You can check the ATX 24-pin 12V Power Supply Pinout to find the locations of these pins.
Step 8: You have to make sure that each voltage you have tested is within approved tolerance. You have to check the power supply voltage tolerances list to know the proper ranges for every voltage. If all the tested voltage is within the tolerance, it indicates that the power supply voltage is correct. Then, you have to turn off the power supply switch again and unplug it from the wall.
Step 9: Now, you have to reconnect all of your internal devices to power. You also have to disconnect the short connection that you have made.
Step 10: You have to plug in your power supply and again flip the switch of the power supply. Then, you have to start your PC with the power button as you always do. The computer won’t open without the cover, so, you have to move the jumper connected to the motherboard.
Step 11: Again, you have to connect all the internal devices. Then, you have to test the other connectors’ voltage such as the peripheral power connectors(PIN 4) and the SATA power connectors. (pin 15)
Step 12: If you don’t know which pin is necessary to check, you may use the ATX Power Supply Pinout Tables list to find the important power connectors which you have to test with the multimeter.
Step 13: Finally, when you test all the power connectors, you have to turn off the pc and put the cover back again to the case.
You can learn more about this topic regarding testing the power supply unit or PSU of a computer. We can suggest you to learn about ports of a computer and USB symbols which are very important for a computer user.
You can test the power supply through the software or you can use a multimeter to test it. It doesn’t matter which method you are trying. You just have to follow the steps properly to test it and compare the test results with the voltage that the pin should have. We can suggest you learn about the ports of a computer and know how you can ping a port and USB symbols which are very important for a computer user.