Microwave runs (light on, fan and turntable operating) but food does not heat at all.
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 access or test the magnetron, transformer, capacitor, or diode unless you are trained and know how to safely discharge the capacitor.
User-level checks:
- 1. Confirm symptom: Heat a cup of water on HIGH for 1–2 minutes. If the water remains cold while the unit appears to run normally, heating has failed.
- 2. Check power supply: Plug the microwave directly into a wall outlet. Avoid extension cords that may cause voltage drop.
- 3. Listen and smell: Note any unusual loud humming, buzzing, or burning smell during operation. These signs point to HV component failure.
Recommendation: Because of the high-voltage risk, internal repair (magnetron, capacitor, diode, transformer, inverter) should be performed by a qualified technician. In many cases, replacing the magnetron or inverter board restores heating.