The detection method is as follows: 1 liter of water to be filled with water containers into the microwave oven cavity, disconnect the 2-pin high-voltage wire connectors CN703, choose a high-power, input 1 minute, then press the "Start" button, after about 23s microwave stopped working, in a microwave oven during operation, the input current is about 0.5A ~ 1A, if the input current is normal, then disconnect 3-pin connector CN701, choose a high-power, input 1 minute, then press the "Start" button, after about 3s, microwave stopped working, in a microwave oven during operation, the input current should be less than 0.4A.pGuservice manual download site