Microwave displays E7 and will not start; clock and basic display still work.

Safety: Unplug the microwave before opening the cabinet.

• Step 1 – Hard reset: Unplug the microwave for at least 10 minutes to allow internal capacitors to discharge and the microcontroller to fully reset. Plug back in and reprogram the clock, then test.
• Step 2 – Check for surge damage: If E7 appeared after a power outage or lightning storm, inspect the control PCB for burnt components or discoloration. Use a surge protector in the future.
• Step 3 – Reseat connectors: With the cabinet removed, gently reseat all low-voltage connectors on the control PCB (keypad, sensors, relays). Ensure no pins are bent.
• Step 4 – Replace control PCB: If E7 persists, the control board is likely defective. Order the correct Bomann control PCB using the full model number and replace it. This involves transferring any mounting hardware and reconnecting all harnesses exactly as before.
• Step 5 – Professional service: If you are not comfortable working with electronics, have an authorized technician replace and test the control board.