Microwave runs but does not heat food; display shows E03 after a few seconds or at the end of the cycle.

Critical safety warning: The high-voltage section of a microwave (transformer, capacitor, diode, magnetron) can store and generate lethal voltages. Do not attempt to service these components unless you are a qualified appliance technician with proper tools and training.

What you can safely do:

• 1. Power reset: Unplug the microwave for 5–10 minutes, then plug back in and test with a cup of water.
• 2. Check outlet and power: Confirm the wall outlet is delivering correct voltage and is not shared with heavy-load appliances that may cause voltage drops.
• 3. Visual inspection (external): Smell for burning odors and look for smoke or scorch marks around the cabinet vents. If present, discontinue use immediately.

Technician-only actions: Testing and replacing the high-voltage capacitor, diode, and transformer require discharging the capacitor and working near high-voltage circuits. This must be done by a professional. Continuing to use a microwave with an E03 error can be hazardous.