Microwave trips the household circuit breaker or blows the main fuse when starting a cooking cycle.

Critical safety warning: Repeatedly resetting a tripping breaker is dangerous. Unplug the microwave and do not use it until the fault is corrected. High-voltage testing must be done by a qualified technician.

• Step 1 – Try a different outlet: Plug the microwave into a known-good outlet on a different circuit (without extension cords). If it still trips immediately on START, the fault is in the microwave.
• Step 2 – Visual inspection: With the unit unplugged and cabinet removed, inspect for burnt wiring, charred components, or melted insulation near the transformer, capacitor, and line filter.
• Step 3 – Technician testing: A technician will isolate and test the HV capacitor, diode, magnetron, and line filter for shorts using a multimeter and insulation tester.
• Step 4 – Replace faulty components: Replace any shorted component with the correct Bomann part. After repair, perform an insulation and leakage test before returning the unit to service.