A power supply tester is an electronic device used to test how well a computer power supply is functioning. This type of testing is often performed as part of maintenance on a computer, and can be used to try to determine the source of a computer problem. It is typically a handheld device that has a number of different plugs that can be connected to the power supply within a computer, and a digital display screen and indicator lights used during the testing process. A power supply tester is fairly inexpensive, but due to its singular usefulness it may not be an investment most people wish to make.
The power supply within a computer is responsible for properly distributing power to the various hardware devices within the computer case. This means that a faulty or malfunctioning power supply can lead to a number of different computer problems, including crashes, lockups, and the computer simply not even starting up. A tester is often used during computer diagnostics to establish whether the power supply is failing, to better narrow down the cause of computer issues.
Despite the importance of the power supply, it is often one of the first parts of a computer to wear out or fail, and checking it with a power supply tester is often the first step in computer diagnostics. There are many cables that run from the power supply to the motherboard and every piece of hardware within the computer. If any of these cables are no longer moving power properly to those devices, then problems can arise.
This is why a tester will usually have several different types of connectors on the device, allowing these different cables to be tested. If there is a problem with the major connection between the power supply and the motherboard, then the power supply will likely need to be replaced. Problems with the other connectors to different devices in a computer can potentially be solved by using a different connector, when one is available. If a power supply tester determines that the power supply is simply not distributing enough power throughout the computer, then the power supply will likely need to be replaced.
Due to the single purpose of a power supply tester, it is a specialized piece of equipment and not something most people are likely to purchase. Other types of power testers such as a multimeter can also be used to test a power supply, but the process can be somewhat more complex. These devices can be used for many different purposes, however, so are more likely to be a useful investment for someone who does not do computer repair professionally.