Microwave runs for 1–2 seconds then stops and shows E03 on the display.

Critical safety warning: The high-voltage section of a microwave (transformer/inverter, capacitor, diode, magnetron) can be lethal. Do not attempt internal HV repairs unless you are a trained appliance technician with proper tools and procedures.

User-level checks:

• Unplug the microwave for 5–10 minutes to allow the control to reset, then plug back in and test.
• Verify that the unit is on a dedicated outlet and not sharing with heavy loads that may cause voltage drops.
• Check for burning smells or unusual noises (buzzing, arcing). If present, stop using the microwave immediately.

Technician-level checks:

• Inspect the inverter PCB or HV transformer area for burn marks, cracked solder joints, or blown components.
• Test the magnetron for shorts between terminals and to chassis.
• Check the high-voltage diode and capacitor with appropriate test methods.
• Replace the inverter module or transformer as a complete assembly per Fagor service documentation.

If E03 reappears after a basic reset, discontinue use and contact a professional; continued operation may cause further damage or fire risk.