Modern computers operate on a power supply that is controlled by logic circuits on the motherboard instead of a physical power switch that controls power. The motherboard always has power and can detect the press of the power switch because the switch is hooked to a small pair of contacts on the motherboard. A computer can be turned on by creating a momentary connection between these two power contacts directly on the motherboard without the need for the power switch.
Things You'll Need
- Small metal object such as a screwdriver, paperclip, or coin.
Remove the case cover from the computer.
Remove the cable marked "Power SW" or "PSW" from the front panel connectors on the motherboard. The cable is typically connected across pins 6 & 8 of the front panel header pin row on many motherboards. Consult the motherboard manual or the website of the motherboard manufacturer for the specific location of the power switch connector on a particular motherboard.
Touch a small metal object onto both of the pins that the "Power SW" or "PSW" connected to for a moment in order to power on the computer.
Power the computer off using the software shutdown interface or hold a metal object over the same two pins for about six seconds until the power shuts off to force the computer to power down.
Tips & Warnings
- Build a small lead with six inches of wire and a front panel connector that can be connected to the power on terminals on the motherboard and simply cross the ends of the wire, or connect a small switch to the end, to power on the system instead of reaching inside the case every time. Alternatively, cut off the lead that runs to the power switch and just cross the ends to start the computer.
- The reset button can also be shorted out to reset the computer manually if desired.
- Do not cross any other connectors on the motherboard and be sure to dissipate any built up static electricity prior to powering on the computer by touching the metal case with a bare hand.
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