Membrane key switch microwave oven key not working what is wrong

FPC membrane key switch microwave oven key is not working what is broken

If the contact is not good, check if the contacts inside are loose. Including the tin point. When the door is closed, is it closed properly? Sometimes there will be looseness here. In addition, the fuse should be twisted tightly, the keyboard input circuit or the single-chip microcomputer input port failure. The microwave light touch membrane switch is a 4×6 matrix switch. Under normal circumstances, when no key is pressed, the 10 lines between the row and column are not connected to each other. When a key is pressed, the corresponding The row and column lines should be connected. For example, when the cooking key is pressed, the wires ① and ⑦ should be connected. The reasons for the failure of the keys are: bad tact switch; loose connection between the tact switch and the connector; cracking and open circuit of the triode, resistor and printed circuit. After inspection, the function of the tact switch is normal, and no abnormality is found in the switch wiring and peripheral components. It is judged that the single-chip microcomputer is damaged. If only a few buttons fail, the micro-buttons embedded inside are aging and fail, and they can be replaced. Some of them are sold at a low price (miscellaneous electricity market). If all of them fail, the internal computer board is faulty, and the entire board is replaced.

Basic requirements for buying a microwave oven

Microwave ovens are the products listed in the first batch of national compulsory safety certification (CCC certification). Consumers must choose products with the "CCC" certification mark and the corresponding factory code and certification number when purchasing. In order to verify the authenticity of the certification marks and certification certificates, you can log in to the official website of the Certification and Accreditation Administration of China to check the certification certificates online.

Check whether the product's instruction manual, certificate, warranty card and accessories are complete.

Carefully check the product's logo and instruction manual. National Mandatory Standard.21-"Special Requirements for Safe Microwave Ovens for Household and Similar Electrical Appliances" stipulates that the identification of microwave oven products should be clear and standardized, and the content should include: trademark, model, specifications (such as capacity), rated voltage, rated input Power, symbol of the nature of the power supply, name of the manufacturer, rated output power, etc.; the instruction manual should contain warnings to prevent misuse and detailed cleaning methods, etc.; the operation switch logo on the product should be clear and reliable.

Check the appearance. The appearance should be flat and smooth, with uniform color and no obvious color difference. In addition, microwave ovens will generate microwaves. When purchasing, special attention should be paid to the sealing condition of the door and whether the door interlocking device is normal.

Add water to test. You can use a glass to add an appropriate amount of water to test the heating. After the microwave oven is energized, the water in the furnace becomes hot. The shorter the heating time, the higher the water temperature, which means the better the heating performance of the microwave oven. At the same time, after allowing the microwave oven to work for a period of time, touch whether the housing of the appliance is hot. If the housing of the appliance is hot, it means that the heat dissipation condition of the appliance is not good.

Choose well-known companies with larger scale, better product quality and better service quality. Because larger-scale production enterprises have stricter quality control of raw materials, parts and products, advanced production equipment, high level of enterprise management, and more guaranteed product quality and after-sales service.