Furnace lights, trays also turn description primary line correctly, failure on the secondary circuit high voltage parts, as long as the magnetic flux leakage transformer, high voltage capacitors, high voltage diode, magnetron tube, such as one of these components fails, will result in no output, it is not heating food. Secondary high voltage side of the transformer plug disconnect the high voltage circuits, compress down, maintenance is relatively safe. Power check the transformer secondary voltage 1800V, respectively, 3. 15V, normal. Multimeter again stop checking high-voltage capacitors, high voltage diode and magnetron tubes, magnetron filament open and pried the magnetron filament in the base, found off filament lead wire welding, use pliers to clamp them, with iron welding in prison immediately after the computer is working properly.