Can I change fan speed

Hi @johnculley

The fan speed is controlled by the BIOS on the motherboard responding to sensors in the CPU and is not user adjustable.

Why do you wish to change the speed?

If the fan is operating on high speed most likely it is just trying to keep the CPU within its temperature operating limits.

If it is always operating at high speed even if there's not much activity happening in the laptop, then it could be a dusty fan and dried thermal paste on the CPU that is the problem as the heat is not being dissipated quickly enough.

Here's the maintenance and service guide for the model series.

Go to p.56 → p.60 (66→70 of 104 pdf) in the guide, to view the procedure to remove the fan and heat sink assembly.

This will allow you to clean the fan (use a soft brush and a vacuum cleaner) and to check and refresh (if necessary) the thermal paste on the CPU.

Here's the ifixit How to Apply Thermal Paste guide that may also help.