Considering three reasons, the key didn't respond. First, poor contact; Second, the keyboard input circuit or the input port of the single chip microcomputer is faulty; Third, individual buttons are aging and invalid. The specific reason why the keys of Galanz microwave oven are unresponsive: 1, poor contact: see if the contacts inside are loose, including tin spots, when closing the door. Is it closed in place? Sometimes it's loose here, so the fuse needs to be tightened. 2. There is something wrong with the keyboard input circuit or the input port of the single chip microcomputer: the thin film touch switch of the microwave oven is a 4×6 matrix switch. Under normal circumstances, 10 lines between rows and columns are disconnected from each other without pressing the key. When a key is pressed, two lines corresponding to the key should be connected. If the cooking key is pressed, wires ① and ⑦ should be connected. The causes of key failure are: poor touch switch; Loose connection between touch switch and connector; Triode, resistor, printed circuit broken virtual welding. After inspection, the function of the touch switch is normal, and there is no abnormality in the switch connection and peripheral components. It is judged that the single chip microcomputer is damaged. 3. If only a few buttons are broken and the embedded miniature buttons are broken, you can choose to replace the computer board with internal faults or the whole electric board.