Galanz Microwave Oven Repair Techniques; Microwave Oven Blows Fuse on Power-On
Fault Symptoms: The fuse blows as soon as the power cord is plugged in.
Analysis and Maintenance: This type of fault occurs in the safety protection circuit. A interlock switch is installed on the microwave oven door. Whether the microwave oven is operating or not, once the door is opened, the interlock switch cuts off the power supply to the magnetron to ensure that no microwave energy leaks out from the cavity. Under normal circumstances, when the microwave oven is not working, both the interlock switch and the monitoring switch are in an open state. If the interlock switch is damaged, it may cause the interlock switch and the monitoring switch to close even when the microwave oven is not in operation, leading to the blowing of the fuse. During maintenance, first unplug the power cord, remove the outer casing, and discharge the high-voltage capacitor; then remove the blown fuse and connect a 220V/15W incandescent bulb across its terminals. Open the oven door and place the microwave oven in normal working condition, then plug in the power. If the bulb lights up, it indicates that the interlock switch is in a closed state, confirming that the interlock switch is damaged.
Repair Measures: Replace the interlock switch with one of the same model to resolve the fault.
Maintenance Experience: When installing the interlock switch, be careful not to break or bend the mounting plate. After installation, a microwave leakage check should be performed.
Source of Information: http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3463515.