Source: Beijing Galanz Microwave Oven After-sales Service Phone Number http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3463515.
Galanz G8023CTL-K3 microwave oven, no power after cooking.
[Malfunction Phenomenon] After cooking, when the oven light was turned on, there was a "pop" sound and then it lost power.
[Reason for Failure] The door monitoring switch assembly has shifted.
[Analysis and Maintenance] Upon opening the microwave oven casing, it was observed that the fuse had blown and turned black, indicating a breakdown or overcurrent in the downstream circuit. After unplugging the power cord and discharging the high-voltage capacitor, components prone to damage such as the high-voltage transformer, secondary high-voltage capacitor, high-voltage diode, and magnetron were checked, with no signs of breakdown or leakage found. It was assumed that the fuse blowing was an isolated incident, but after replacing the fuse and testing the machine, although the microwave oven heated normally, the fault reoccurred upon opening the door. This indicates that the fault is related to the door switch. This microwave oven is equipped with three door interlock switches, whose on/off states are controlled by the door lever assembly, which in turn is controlled by the door mechanism located in the middle of the oven door. Observing the two door hooks and the door lever assembly on the oven door, there were no obvious signs of wear or breakage, and the three door switches could normally switch between on and off. Considering that the impact when closing the oven door may be significant and could cause the door switch assembly to shift over time, this might result in the S3 door monitoring switch closing as required when the door is opened, while the S1 first-level interlock switch does not immediately disconnect as designed, causing the S1 and S3 series connection to short-circuit the 220V power supply, thereby blowing the FUSE fuse. Therefore, after adjusting the position of the first interlock switch, the fault was eliminated.
[Warm Reminder] The microwaves produced by the magnetron in the microwave oven are emitted via the magnetron's antenna and delivered to the oven cavity through a dedicated waveguide to heat food. Since microwaves are harmful to the human body, the three interlock door switches set in the microwave oven provide triple protection to prevent the microwave system from operating when the oven door is open.