Microwave runs but does not heat food; turntable and light work, timer counts down normally.

Critical safety warning: The no-heat condition almost always involves the high-voltage system, which is extremely dangerous. Unplug the microwave and do not attempt internal HV repairs unless you are qualified.

• Basic checks:
  • Verify you are using microwave-safe containers and not metal or foil.
  • Test with a cup of water for 1–2 minutes. If the water stays cold, heating is not occurring.
• Technician-level diagnosis:
  • Remove the outer cover and visually inspect the magnetron, HV transformer, capacitor, and diode for burn marks or damage.
  • Discharge the capacitor safely using a resistor and insulated tools.
  • Test the diode and capacitor with appropriate meters; replace if defective.
  • If all HV components test good, the magnetron itself may be weak or open and should be replaced with an Ambiano-compatible magnetron.

Recommendation: For many Ambiano countertop microwaves, replacing the entire unit may be more cost-effective than replacing multiple HV components.