An ATX SMPS (switched-mode power supply) is a type of computer power supply that is designed to meet the ATX form factor. ATX power supplies are typically used in desktop computers, and they provide power to the motherboard, CPU, graphics card, and other components. Checking an ATX SMPS is important to ensure that it is functioning properly and that it is providing the correct amount of power to the components in your computer.
There are a few different ways to check an ATX SMPS. One way is to use a multimeter to test the output voltages of the power supply. Another way is to use a power supply tester. Power supply testers are designed to test the output voltages of a power supply and to indicate whether the power supply is functioning properly.