Desktop CPU 12-Volt Power Path: Shorted PSU output rail | Auckland
Pattern to record: The supply clicks or refuses to start until a connector is removed.
Identify the supply and load
The EPS/CPU connector feeds the motherboard’s processor regulators. Verify the cable against the PSU and board documentation; a PCIe graphics cable is not interchangeable just because a similar plug appears to fit. One possible explanation is that a cable, peripheral or internal supply component pulls one rail down.
Mains and connector safety
PCIe and CPU power plugs can look similar but are not interchangeable. Hot-plugging internal power connectors can destroy hardware.
Workshop checks
- Verify the correct CPU power cable, connector condition and VRM input stability.
- Disconnect mains, isolate branches and measure resistance before applying power.
Repair and loaded verification
If the checks support this cause, repair the downstream short or replace the failed supply. Verification should cover cold POST, processor stress, sleep, restart and connector temperature.
For an assessment of your desktop motherboard, contact AEPC in Burswood or call 027 908 8880. Provide the model and the conditions that reproduce this problem. Workshop visits are by appointment.