Most of us switch off our computers using a power switch. However, most of us don’t know where does this switch lies on the motherboard. Generally, you can find the power switch located at the back panel or front panel (it depends on your case).
When building or upgrading a computer, installing the power supply is the first step for many people. Right next to the ATX connector on the motherboard lies another set of connectors: one usually green with an “E” in it, and another black or blue. These are the location of your power switch leads that get connected to the case power switch.
The black, three-pin lead goes into a “P” connector on the motherboard and is for 5V standby power when the ATX12V1/2 lead is not connected. A lot of people are confused about this sometimes confusing fact about the location of your motherboard’s power button. If you don’t have a physical switch on your case, you’ll need to run this lead to an unused fan header.
The green, five-pin connector is the ATX12V1/2 lead and gets connected to a 12 Volts power source found in any modern computer. If you are building or upgrading a PC, it’s usually pretty easy to get this connector hooked up. In fact, they are often in the same place on your case. The lead that you need to carefully examine is the black or blue wire with a white stripe. When building your PC, you will need to connect this lead from either an unused fan header of two on your motherboard and then into a P connector on your case. This will complete the power circuit for when you are powering up or down your computer with a physical switch either on the case or the motherboard itself.