cpu cooling fan not working

[sameerakelum]

A USB device short-circuited while connected to my HP ProBook 440 G8, causing the laptop to power off completely. After performing a battery disconnect/reconnect reset, the laptop powers on again, but the CPU cooling fan is no longer working.

Sequence of Events & Symptoms
Short Circuit: A short circuit occurred through one of the USB ports.

Power Loss: The laptop immediately shut down and would not respond to the power button.

Battery Reset: I opened the laptop, disconnected the main battery, and reconnected it.

Current Status: The laptop turns on and boots up, but the CPU cooling fan does not spin at all, leading to high temperatures/overheating risks.

Questions for the Community / Support
Could the USB short circuit have damaged the CPU fan controller chip or fuse on the motherboard?

Is there a reliable way to test if the issue is with the fan unit itself or the motherboard header/circuit?

What are the recommended troubleshooting steps or replacement options for this repair?

[Kuroi_Kenshi]

Hi @sameerakelum,

Welcome to the HP Support Community!

Thank you for reaching out.

I understand your concern. Since the cooling fan stopped working immediately after a USB short circuit, it is possible that the short affected a motherboard component responsible for power distribution or fan control. However, before concluding that the motherboard is damaged, let's perform a few checks to isolate whether the issue is with the fan itself or the system board.

Check the fan in HP Hardware Diagnostics

Turn off the notebook.

Power it on and immediately tap the Esc key repeatedly.

Press F2 to open HP PC Hardware Diagnostics UEFI.

Run the Component Tests > Fan Test (if available).

If the fan test fails or the fan is not detected, make a note of any failure ID displayed.

Check the BIOS

Restart the notebook and press F10 repeatedly to enter the BIOS Setup.

Check whether the fan is reported normally or if any system fan (90B) or cooling-related warnings are displayed.

Save and exit without making changes.

Inspect the fan connection

Since you've already opened the notebook:

Power the notebook off and disconnect the AC adapter.

Remove the bottom cover.

Verify that the fan cable is fully seated on the system board and was not loosened when disconnecting or reconnecting the battery.

Check for any visible signs of burn marks or damage around the fan connector and the affected USB port.

Update the BIOS

If the notebook remains stable long enough to boot into Windows, install any available BIOS update from the official HP Support website for your exact model. This can help if the embedded controller is no longer communicating correctly with the fan.

Kindly Update BIOS using the following link

https://support.hp.com/us-en/document/ish_4123786-2338478-16

Until the issue is resolved, avoid running CPU-intensive applications. If the fan is not operating, the notebook may overheat and shut down to protect the hardware.

Based on the sequence of events you described, it is possible that the USB short damaged the fan power circuit, embedded controller circuitry, or another motherboard component. If the fan does not operate during the HP Hardware Diagnostics fan test and the cable connection is secure, the issue will likely require a hands-on hardware diagnosis to determine whether the fan assembly or the system board needs replacement.

Let me know how it goes.

Take care and have an amazing day ahead! 🚀

Best regards,

Kuroi_Kenshi