Why does my fan constantly spin?

Hi @tumble220 ,

Could you elaborate a bit on your question?

Most fans spin for most of the time when a laptop is in use.

For example, do you mean that it continually operates at high speed and therefore is noisier than normal?

It may be a motherboard issue but first you could check the condition of the thermal paste on the CPU to see if it has dried out and needs refreshing. See YouTube videos for how to refresh the thermal paste on a CPU. Dried out thermal paste means that the heat from the CPU is not as efficiently transferred to the heat sink and then extracted by the fan, so the CPU runs hotter. The CPU has an inbuilt thermal sensor designed to signal the BIOS to increase/decrease the fan speed to extract the air more/less quickly when the temperature reaches certain thresholds

It could also be a problem with the fan itself. Looking at the ifixit Asus K50IJ Fan Replacement guide, the fan has 4 wires so this may mean that it has an inbuilt temperature sensor (thermistor) and a rpm sensor to signal information to the BIOS, about the temperature of the air passing through the fan and the speed of the fan i.e. to indicate that it is operating, so that the fan speed can be adjusted as necessary to suit the operating conditions at the time.

If the thermal paste appears to be OK, then check what the laptop is doing at the time. There may be more going on in the background so system resources may be being utilized unnecessarily, placing an extra burden on the CPU.

If Win 10 is installed right click on the Taskbar and select Task Manager. When in Task Manager click on the Processes tab to view the % of the CPU, memory and disc and check what is happening if the CPU % is high in relation to what is happening. Also check the Startup tab to view what programs are being loaded at startup and if they are necessary at all. If you don’t know what they’re for Google the name and find out what they do. Some are necessary but some are installed and are not used that often but they’re still using system resources. You can disable them by right click on the program > disable and check if things improve. If disabling causes problems simply go back and right click > enable them again. You will have to restart the laptop after disabling/enabling for the changes to come into effect.

Apologies for the long answer but potential overheating problems can have many causes and they have to be eliminated one by one