cooling fan is not operating correctly 90B

[Ameer_Husam]

[Hawks_Eye]

Hi @Ameer_Husam 

Welcome to the HP Support Community! We're here to help you get back up and running.

The “System Fan (90B)” error means your HP device has detected that the cooling fan isn’t functioning properly. This can lead to overheating and potential damage if not addressed. 

Fortunately, there are steps you can take to resolve it.

What to do when you see the 90B cooling fan error

Power down and inspect for dust buildup

• Shut down the device and unplug it.
• Use compressed air to gently blow into the fan vents—especially along the rear and sides.
• Dust accumulation is a common cause of fan malfunction and restricted airflow.

Check for physical obstruction or damage

• If you're comfortable opening the bottom panel, inspect the fan for loose cables, debris, or signs of wear.
• Make sure the fan blades spin freely and aren’t blocked.

Update BIOS and system firmware

• Visit the HP BIOS recovery and update guide.
• Enter your exact model number and download the latest BIOS update.
• Install it using the HP App or directly from a USB if needed.

Run HP Hardware Diagnostics

• Power on and immediately press Esc, then F2 to open HP PC Hardware Diagnostics.
• Select System Tests > Extensive Test and let it run.
• This will check fan performance and other components.

Reset BIOS settings to default

• Enter BIOS setup by pressing Esc or F10 during startup.
• Navigate to Exit > Load Setup Defaults, then save and exit.
• This can clear any misconfigured thermal settings.

Avoid using the system until resolved

• If the fan isn’t spinning or the error persists, avoid prolonged use.
• Overheating can cause shutdowns or hardware damage.

If the fan remains non-functional after cleaning and BIOS updates, it may need replacement. 

Let me know your exact model number and I can guide you to the correct part or service options. I’ll stay with you until your system is cool, quiet, and running safely again.

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Take care, and have an amazing day!

Regards, 

Hawks_Eye