Microwave runs but does not heat and shows E03 after a few seconds; turntable and light may still operate.

Critical safety warning: The high-voltage section of a microwave (transformer, capacitor, diode, magnetron) can be lethal even when unplugged. The capacitor can hold a dangerous charge. Do not attempt to service these components unless you are trained and have proper tools to safely discharge the capacitor. For most users, this is a technician-only repair.

Basic user checks (non-invasive):

• 1. Confirm symptom: Place a cup of water in the cavity and run for 1–2 minutes. If the water remains cold and E03 appears, heating is not occurring.
• 2. Check power supply: Ensure the microwave is on a dedicated outlet and not sharing a circuit with heavy appliances that could cause voltage drops.
• 3. Visual inspection only: With the unit unplugged and outer cover removed, look (without touching) for obvious burn marks, melted wiring, or a bulging capacitor. If seen, do not power the unit again.

Technician-level actions (for professionals only):

• Discharge the high-voltage capacitor safely.
• Test the high-voltage diode, capacitor, transformer windings, and magnetron for continuity and shorts.
• Replace the failed component(s) with Paderno-compatible parts and re-test.

If you are not qualified, stop here and arrange professional service.