Microwave does not heat food; display shows E03 after a few seconds of operation.

Critical safety warning: High-voltage components inside the microwave can exceed 4,000 V and remain charged after unplugging. Only trained technicians should service the high-voltage section. Do not attempt to discharge the capacitor without proper tools and training.

• Step 1 – Basic checks: Confirm that the turntable rotates and the interior light comes on when you start a heating cycle. If these work but there is no heat and E03 appears, the fault is likely in the high-voltage circuit.
• Step 2 – Visual inspection (low-risk only): With the unit unplugged and outer cover removed, visually inspect for obvious burn marks, melted connectors, or a cracked high-voltage diode casing. Do not touch the capacitor or transformer.
• Step 3 – Professional testing: Testing the magnetron, transformer, capacitor, and diode requires specialized procedures and insulated tools. Contact an AEG-authorized service center to measure component values and insulation resistance.
• Step 4 – Part replacement: If the magnetron is confirmed faulty, replace it with the exact AEG-specified magnetron model. Always replace any burnt wiring and check the cooling system to prevent repeat failure.