Windows & BSOD · high

How to fix CPU Fan Error (POST)

Windows & BSOD troubleshooting guide

What this error means

The motherboard BIOS cannot detect a CPU fan signal during POST. System may refuse to boot to protect the CPU. The usual suspects are fan not connected to CPU_FAN header and faulty fan motor.

Updated

Before you begin

Save open work and back up important files. Use instructions for your exact device and software version. If Windows cannot start, see the startup guide.

Work through these checks

0 of 3 complete
01Check connection to CPU_FAN header
  1. Check connection to CPU_FAN header
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

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02Lower 'CPU Fan Speed Lower Limit' in BIOS
  1. Lower 'CPU Fan Speed Lower Limit' in BIOS
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
03Replace CPU cooler
  1. Replace CPU cooler
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors

Possible causes

  • Fan not connected to CPU_FAN header
  • Fan speed too low for BIOS threshold
  • Faulty fan motor

Useful Windows tools

These commands open Windows tools. Review changes before applying them.

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