PC powered on with the audio jack by a tech tinker

A self-described tech tinker wired a TRS/TRRS audio connector to the appropriate header on a motherboard and used it to power on a PC. PC power buttons, the piece explains, are just a bit of metal that you press against two electrical contacts; the resulting current flow is detected by the motherboard, which then tells the power supply unit to start.

Lee successfully boots the PC within a few seconds of wiring up the connector. There is a small flaw: leaving the audio jack in the socket replicates the same function as holding down the power button for a few seconds, so the PC powers off. A power button only momentarily joins the contacts; the "click" you hear is the mechanism releasing itself.

A TRS/TRRS socket has no mechanical movement, so to break the contact the only way would be a little timing circuit that effectively drops the connection after a second or so.

trs connector, trrs connector, audio jack, motherboard header, power button, pc power, power supply, momentary switch, timing circuit, hardware hack