Microwave runs but does not heat; display shows E03 after a few seconds.

Safety first: Unplug the microwave. The high-voltage capacitor can store a lethal charge even when unplugged. Do not attempt to discharge or service the HV section unless you are trained and equipped.

• 1. Confirm symptom: Place a cup of water inside and run for 1–2 minutes. If the turntable and light work but the water remains cold and E03 appears, the control is detecting a heating fault.
• 2. Basic external checks: Ensure the unit is on a dedicated outlet and not on an overloaded extension. Low supply voltage can sometimes trigger heating errors.
• 3. Internal diagnosis (for professionals only): With the cover removed and capacitor safely discharged, test the high-voltage diode and capacitor with appropriate methods, and check transformer windings for continuity. Replace any failed component with Beko-compatible parts.
• 4. Magnetron check: Inspect the magnetron for burn marks, cracks, or a burnt smell. Test filament continuity. Replace if defective.

Warning: Due to the extreme danger of the high-voltage circuit, non-professionals should not attempt internal repairs. If E03 appears, contact an authorized Beko service center.