How do you test and replace a faulty power supply unit?

1 Identify the PSU

The first step is to identify the PSU in your computer. The PSU is the metal box that connects to the power cord and distributes electricity to the motherboard and other components. It usually has a fan and a label with its specifications, such as wattage and voltage. To access the PSU, you need to open the case of your computer and locate it, usually at the top or bottom. Make sure you unplug the power cord and any other cables before opening the case.

2 Test the PSU

The next step is to test the PSU to confirm that it is faulty. There are two ways to do that: using a multimeter or a PSU tester. A multimeter is a device that measures electrical current, voltage, and resistance. A PSU tester is a specialized tool that plugs into the PSU connectors and displays the output values. To use either method, you need to disconnect the PSU from the motherboard and other components, and then jump-start it by connecting the green wire and any black wire on the 24-pin connector with a paper clip or a wire. This will turn on the PSU without the power button. Then, you can measure the voltages on the different connectors and compare them with the standard values. If any of the voltages are out of range, the PSU is faulty and needs to be replaced.

3 Choose a new PSU

The third step is to choose a new PSU that is compatible and adequate for your system. You need to consider several factors, such as the size, the wattage, the efficiency, and the connectors. The size of the PSU depends on the form factor of your case and the space available. The wattage of the PSU depends on the power consumption of your components and the headroom for future upgrades. You can use online calculators or tools to estimate your wattage needs. The efficiency of the PSU depends on how well it converts AC power to DC power and how much heat it generates. You can look for PSUs with 80 Plus certification, which indicates different levels of efficiency. The connectors of the PSU depend on the types and number of components you have. You need to make sure that the PSU has enough connectors for your motherboard, CPU, GPU, drives, and fans.

4 Install the new PSU

The fourth step in installing a new PSU in your computer is to remove the old PSU from the case and disconnect it from the power cord. Then, place the new PSU in the same position as the old one and secure it with screws. Next, connect the power cord to the new PSU and plug it into a wall outlet. After that, connect the 24-pin connector to the motherboard and the 4-pin or 8-pin connector to the CPU. Additionally, if you have a GPU, connect the 6-pin or 8-pin connectors to it. Finally, attach the SATA or Molex connectors to the drives and fans and tuck away any excess cables before closing up the case.

5 Test the system

The final step is to test the system to ensure it functions properly. To do this, turn on the power switch on the back of the new PSU and press the power button on the front of the case. Monitor the boot process and look for any errors or warnings. Additionally, run some diagnostic tools or benchmarks to test performance and stability. If everything works fine, you have successfully replaced your faulty PSU; if not, you may need to troubleshoot other hardware issues or contact a professional.

6 Here’s what else to consider

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