ModMyMods ATX 24 Pin PSU Jumper Switch Red Light CAB285

ATX 24 Pin Power Supply Jumper

This ATX 24 pin jumper lets you start a power supply without a motherboard. It replaces the paperclip method with a proper switch and a red indicator light. The unit plugs into the PSU 24 pin connector and mimics the motherboard power-on signal. It is aimed at builders testing units on the bench or running pumps during loop filling.

Manual On Off Switch Limits

The switch only bridges the green wire to ground, so the PSU starts but no motherboard supervision is present. Voltage regulation, fan curves and protection circuits remain entirely under the power supply's internal logic. There is no data communication, no monitoring header and no software control. The red LED simply shows that the jumper is active.

Bench Testing And Loop Filling Headroom

The jumper comfortably handles ATX supplies up to their rated wattage because it passes no load current itself. It runs out when a build requires motherboard handshake signals such as power-good timing or SMBus telemetry. For permanent installations or multi-rail sequencing a different solution is needed.