LG No Microwave Generation (Heating Failure)

Microwave runs but does not heat food; turntable rotates and light is on, but food remains cold.

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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

Failed magnetron, Defective high-voltage diode, Open high-voltage capacitor, Faulty high-voltage transformer or inverter board

How to Fix / Troubleshooting

Critical safety warning: Unplug the microwave immediately. The high-voltage system (magnetron, capacitor, transformer/inverter) is extremely dangerous. Do not open the cabinet or attempt internal repairs.

User-level checks:

  • Verify cook settings: Ensure you are not in a low power or defrost mode that may heat slowly. Test with a cup of water on full power for 1–2 minutes.
  • Check door closure: Make sure the door closes firmly; if the door switches are not engaged, the unit may appear to run without energizing the magnetron.

If the microwave consistently fails to heat, internal high-voltage components must be tested and replaced by a qualified technician. Continued use is not recommended.

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Repair Difficulty

Professional Required 5/5

Required Part

Magnetron
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