Power supply fan failure or stuck in Eco mode
The cooling fan inside the power supply fails to spin under load, causing internal capacitors to overheat and trip over-temperature protection (OTP).
Internal desktop parts run on harmless 12V DC voltage and cannot shock you. Simply unplug the wall power cable first, then touch the unpainted metal case frame to ground static electricity.
Common Symptoms & Tells
- PC shuts down instantly without warning during heavy gaming sessions
- Top or bottom of the PC chassis above the shroud is burning hot to the touch
- Flashlight inspection reveals the fan is completely still even during gaming
Interactive Fix Checklist
0 of 5 steps completedSafety power-off and discharge
Shut down the PC, turn off the power supply rocker switch (O), and unplug the AC power cord from the wall outlet. Press the front power button once while unplugged to discharge residual capacitor energy before touching any internal components.
Toggle the PSU Eco / Hybrid / Zero-RPM switch
Many high-end PSUs (EVGA, Seasonic, Corsair) feature a toggle switch on the back for 'Eco Mode' or 'Hybrid Fan'. Flip it OFF to force the fan to spin continuously.
Clean dust buildup inside PSU shroud
Use compressed air through the fan grille. (WARNING: Never open a power supply casing; internal capacitors carry lethal electric charges even when unplugged). SAFETY: Hold the fan blades still with a finger or non-conductive tool while spraying compressed air. Allowing fans to free-spin rapidly can burn out bearings and generate reverse voltage back into the motherboard fan header.
Verify PSU orientation (fan facing fresh air)
If the PC sits on a desk, ensure the fan faces downward toward the case bottom dust filter (or upward if the case floor is completely solid).
Replace the power supply unit
If the fan does not spin when Eco mode is disabled and the unit trips off under load, the internal fan controller or bearing has failed; RMA or replace the .
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