Microwave displays F6 and may not heat or may shut down unexpectedly.

Critical safety warning: The inverter and high-voltage system in a microwave can store and generate lethal voltages. Do not attempt live testing unless you are trained and equipped. For most homeowners, diagnosis beyond visual inspection should be left to a professional.

• Power reset: Disconnect power for 10–15 minutes, then restore and test. If F6 reappears quickly, continue.
• Check ventilation: Ensure all Viking microwave vents are clear of obstructions and that the unit has proper clearance. Overheating can trigger inverter faults.
• Access inverter area: Remove the outer cabinet to visually inspect the inverter board (usually near the magnetron). Look for burn marks, cracked components, or loose connectors.
• Reseat connectors: With power off, firmly reseat the harness connectors between the main control board and the inverter board.
• Replace inverter or control board: If F6 persists, the inverter board is the most common failure. Replace with the correct Viking inverter module. If a new inverter does not resolve the issue, the main control board may also need replacement.
• Professional service: Due to high-voltage risks, consider having a Viking-authorized technician perform inverter and magnetron diagnostics.