Computer host fan noise problem

You can open the case cover yourself to check the dust on the CPU fan, and you don't need to prepare your own technical tools: a small brush (the smallest model for drawing), a hair dryer, and a Phillips screwdriver (some for opening the case cover can be screwed by hand). Clean up the dust on the fan blades with a small brush when opening the chassis. Remember to be careful and then blow it clean with a hair dryer. According to the information you provided, it is estimated that the copper shaft of the fan is short of oil. Without maintenance experience, it is recommended to replace it with a new one, and the cooling fan is generally not expensive, ranging from 10 to 100 yuan (the specific fan cannot be recommended because the CPU model is not provided). It is recommended to call professionals to deal with the mainframe.