The power switch pins

computer-buildingmotherboardpowerpower supply

I’m custom building a PC. I’m using an MSI Z97 PC Mate motherboard. The big power supply is an EVGA 430W. It’s all plugged in, and I hit the switch but it doesn’t do anything. Both JPWR 1 and 2 are plugged in. A photo tutorial (pictured in this link) mentioned some “power switch pins.” Am I missing something?

From the tutorial:

You will need to locate the power switch pins. They are located at the
bottom of the board. They are illustrated in your manual as well. I
like to pull out the wire for the power switch in the case and connect
that to initiate the power. But all you have to do is create a
connection between the two pins.

Best Answer

The power supply switch does not turn on the computer, only the power supply itself. You need to plug the wire from the power button on the case into the motherboard and push the power button to turn the system on.

  • The power switch you're referring to is for the power supply itself. This does not by itself turn on the computer; it merely allows the system to be powered on. JPWR1 (24 pins) is the main ATX power connector, while JPWR2 (8 pins) is the CPU power connector. These pins supply power to system components, and themselves do not turn the computer on.

  • You need to connect the power button/front panel cable from your case onto the motherboard and push the power button on the case to actually turn the system on. On this motherboard, you'll need to connect the cable to a pin header labeled JFP1. Consult the motherboard's manual to determine the correct pinout. In your case (see pinout below):

    • Power SW to 6 and 8 (doesn't matter which way, the pins are just shorted when you press the power button).
    • Reset SW to 5 and 7 (again, doesn't matter which way).
    • HDD LED to 1 and 3 (the red wire should be in 1 as that's the + connector).
    • +P LED to 2, -P LED to 4.

Pinout for JFP1 and JFP2

  • Note that some motherboards (though not the MSI Z97 PC Mate) have a power button which can be used to turn the system on as well.

Note to readers: I walked the user through the installation on Stack Exchange Chat. The transcript is available here.

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