Microwave runs but does not heat food; turntable and interior light work normally.

Critical safety warning: The high-voltage section of a microwave is extremely dangerous. Do not attempt to test or replace the magnetron, capacitor, diode, transformer, or inverter unless you are trained and can safely discharge the capacitor.

• Step 1 – Confirm symptom: Place a cup of water in the cavity and run the microwave at full power for 1–2 minutes. If the water remains cold and the unit sounds normal, heating is not occurring.
• Step 2 – Basic checks: Ensure you are not using metal containers or foil, which can affect heating. Try a different food item to rule out perception issues.
• Step 3 – Internal diagnosis (technician level): With the cabinet removed and the unit unplugged, a technician will test the high-voltage fuse, diode, capacitor, transformer/inverter, and magnetron using appropriate procedures.
• Step 4 – Part replacement: The most common failures are the magnetron, HV diode, or capacitor. These must be replaced with Bomann-compatible parts of the same rating.
• Step 5 – If unqualified: Discontinue use and contact an authorized Bomann service center. Do not continue operating a microwave that does not heat.