OK
No Power / Main Fuse or Power Input Failure
Microwave does not power on at all; display is blank and no lights or sounds
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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.
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Possible Causes
Blown main ceramic fuse, Faulty power cord, Failed line filter board, Open thermal fuse on cavity or magnetron
How to Fix / Troubleshooting
Safety: Unplug the microwave before any disassembly. Internal components can be hazardous.
- 1. Check outlet and breaker: Test the wall outlet with another appliance. Reset any tripped breaker or GFCI.
- 2. Inspect power cord: Look for visible damage. If damaged, replace the cord or have it replaced.
- 3. Access main fuse: Remove the outer cover and locate the main ceramic fuse near the power cord entry or line filter. Test with a multimeter for continuity. Replace only with the same rating if blown.
- 4. Check thermal fuses: Locate thermal fuses on the cavity or magnetron. Test for continuity; replace any that are open.
- 5. If fuses blow again immediately: There is likely a deeper fault (shorted transformer, capacitor, or control board). Professional diagnosis is recommended.
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Repair Difficulty
Medium
3/5
Required Part
Main Ceramic Fuse
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