Two common faults of microwave ovens are mostly related to membrane switches or FPC printed circuits:

(1) Failure of most switches in the keyboard. Leakage of electricity on thin-film switches or FPC is a common cause of such failures. Leakage is caused by long-term damp or moisture erosion on the microwave computer board. Moreover, it is sometimes difficult to judge whether there is electricity leakage from the appearance of the circuit board, so if necessary, you can directly use absolute alcohol to wipe or clean the membrane switch, FPC and computer board. This kind of failure may also be caused by several disconnections in the FPC printed circuit at the same time, but this is basically caused by improper maintenance, so it is relatively rare. When checking, just use the naked eye or measure with a multimeter, you can quickly check the fault, and re-weld the broken wire to eliminate the fault.

(2) Failure of individual switch in the keypad. The broken FPC circuit corresponding to the failed switch or poor contact of the membrane switch is the main cause of this failure. The membrane switch corresponding to the failed switch can be found to eliminate the fault.