Windows & BSOD · high

How to fixCPU-FAN-ERROR

CPU Fan Error (POST)

What this error means

CPU-FAN-ERROR shows up as a high-severity Windows operating system fault. 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. Use the steps below to track down and fix the cause.

Before you begin

Save open work and back up important files. Note any recent driver or hardware changes. If Windows cannot start, use the startup guide first.

Work through these checks

0 of 3 complete
01Check connection to CPU_FAN header

Check connection to CPU_FAN header.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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02Lower 'CPU Fan Speed Lower Limit' in BIOS

Lower 'CPU Fan Speed Lower Limit' in BIOS.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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03Replace CPU cooler

Replace CPU cooler.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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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 any action inside the tool before applying changes.

msinfo32