A PSU, or power supply unit, is a component in a computer that converts mains AC power to the DC power that a computer requires. It is an essential component in a computer, as without it the computer would not be able to function.

The PSU is a metal box that sits inside the computer case and has a number of cables coming out of it. The cables go to the motherboard, the graphics card, the hard drive, and any other components in the computer.

The PSU converts the AC power to the DC power that the computer requires by …