Microwave trips the household circuit breaker or blows a fuse when starting a cook cycle.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Repeatedly resetting a breaker on a shorted appliance is dangerous. Unplug the microwave and do not attempt further operation until the cause is identified.
User-level checks:
- 1. Try a different outlet: Plug into a known-good, dedicated outlet (no extension cords) to rule out wiring issues.
- 2. Observe when it trips: If the breaker trips immediately when START is pressed, a short in the high-voltage or input circuit is likely.
- 3. Visual inspection: With the cover removed (and unit unplugged), look for obvious burn marks on the high-voltage capacitor, diode, transformer, or line filter board. Do not touch these components.
Because this involves high-voltage parts, further diagnosis and replacement should be performed by a qualified technician.
Repair Difficulty
Required Part
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