What is the reason why the cooling fan does not turn after a few months?

The cooling fan does not turn is a serious problem. After using the cooling fan for a few months, the customer has a reaction that the cooling fan does not turn. What is the problem? There are most of the following possibilities: 1. If there is no current when energized, then it is not energized, possibly because the motor is broken, the IC is burned, the wire is disconnected, or the welding is poor, etc. 2. If the current is high, but it does not turn, it may be The motor is short-circuited, or the IC is damaged, or the fan blades are stuck. 3. If there is current when the power is on, but it will turn after pulling it by hand, this is a poor startup. It may be a dead spot. The fan does not turn. It is best to return to the heat dissipation. Fan manufacturer, let the manufacturer analyze the cause, find the true cause, and solve the problem