Microwave displays E5 and will not start; sometimes occurs after repeated use at high power.

Safety first: Unplug the microwave before inspection.

Ventilation and fan checks:

• Check vents: Make sure side, rear, and top vents are not blocked by walls, cabinets, or objects. Provide at least several inches of clearance.
• Clean vents: Use a vacuum or brush to remove dust and grease buildup from intake and exhaust vents.
• Listen for fan: During operation (before the error appears), listen for the internal cooling fan. You should hear a steady airflow sound from the side or rear. If the fan is silent or intermittent, the fan motor may be failing.

Advanced (technician-level):

• Remove the outer cover and visually inspect the cooling fan assembly near the magnetron and transformer.
• Check that the fan blades spin freely and are not obstructed.
• Test the fan motor for continuity and proper voltage when the unit is running.

If the fan motor or thermostat is defective, they must be replaced with compatible Farberware parts. Because this requires working near high-voltage components, professional service is recommended.