Microwave displays F8 and may shut down or refuse to start, often related to cooling or convection functions.

Safety: Disconnect power. Internal fans are near high-voltage components; avoid contact with the capacitor and magnetron.

• Check airflow: Ensure the microwave's external vents are not blocked and that installation clearances meet Monogram specifications.
• Listen for fan operation: During a cook or convection cycle (before the error appears), listen for the cooling or convection fan. No fan sound suggests a failed motor or power issue.
• Inspect fan area: Remove the outer cover (for built-in units, follow installation manual) and visually inspect the cavity cooling fan and convection fan for obstructions, grease buildup, or seized blades.
• Test fan motor: With power disconnected, spin the fan blades by hand. They should move freely. If stiff or locked, replace the fan motor.
• Electrical test: Check continuity of the fan motor windings with a multimeter. Open windings indicate a bad motor.
• Replace faulty fan: Install the correct Monogram cooling fan motor or convection fan motor and reassemble. If fans test good, suspect the electronic control board.