Microwave displays E16 and makes an unusual humming or buzzing noise without heating properly.

Critical safety warning: The high-voltage capacitor can retain a dangerous charge even when unplugged. Only trained technicians should service the high-voltage circuit.

• Step 1 – Stop using the microwave: If you hear loud humming or buzzing and food is not heating, discontinue use to prevent further damage.
• Step 2 – Visual inspection only: With power disconnected, you may remove the cover and visually inspect for burnt wiring or components near the high-voltage section. Do not touch or disconnect any high-voltage parts.
• Step 3 – Professional diagnosis: Have an authorized Bertazzoni technician test the high-voltage diode, capacitor, and magnetron and replace the defective component(s).

Because of the risk of electric shock and microwave leakage, do not attempt DIY repair on the high-voltage system.