ATX Desktop Power Supply: Overcurrent protection trip | Auckland
Pattern to record: Fans twitch or the PC turns off instantly with one load connected.
Identify the supply and load
An ATX power supply provides several outputs and startup signals. Document the PSU model and connected loads; a spinning fan or a simple unloaded start test does not establish stable operation under load. One possible explanation is that the supply detects excessive current and shuts down to protect itself.
Mains and connector safety
Power supplies contain lethal mains sections and should not be opened casually. Repeatedly defeating protection can burn connectors and board traces.
Workshop checks
- Measure standby and loaded rails with known hardware while separating PSU from board faults.
- Isolate loads and compare rail resistance before substituting a known supply.
Repair and loaded verification
If the checks support this cause, repair the shorted component or replace the supply if protection is faulty. Verification should cover cold start, processor and graphics load, sleep, restart and all required connectors.
For an assessment of your desktop PC, contact AEPC in Burswood or call 027 908 8880. Provide the model and the conditions that reproduce this problem. Workshop visits are by appointment.