First, it can be used, but the microwave oven is not heated. Firstly, the main power supply of high voltage transformer is measured, and then the maintenance range is determined according to the measurement results. . If the primary of the high voltage transformer is not supplied by AC220V and the microwave oven is mechanically controlled, check the timer and door switch; When the computer controls the microwave oven, check the door switch, computer board fire relay and drive transistor. Second, what if the microwave oven only gets hot? 1. Check whether the voltage is not enough, so the microwave oven turns, but it is not hot. 2. Check whether the connecting wire of the microwave oven falls off. The connecting wire has dropped, and the microwave oven won't.