Microwave runs but does not heat food; turntable rotates and light is on, but food remains cold.
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
Critical safety warning: The high-voltage section of a microwave is extremely dangerous. Do not attempt to service the magnetron, transformer, capacitor, or diode unless you are trained and know how to safely discharge capacitors.
User-level checks:
- 1. Confirm symptom: Heat a cup of water for 2–3 minutes. If the water is still cold and the unit sounds normal (no loud buzzing or arcing), the HV system is likely faulty.
- 2. Check door seal and latches: Ensure the door closes firmly and the latch clicks. A door switch fault can also cause no-heat, but usually the unit will not run at all.
- 3. Inspect waveguide cover: Look for a burnt or damaged mica waveguide cover. Replace if burnt, as arcing can damage the magnetron.
Recommendation: For most users, a no-heat condition requires professional diagnosis and replacement of the magnetron or HV components. Continuing to run the microwave without heat can cause further damage.