Microwave displays E-13 and may not start or may shut down during operation.

Safety: Unplug the microwave. High-voltage components near the magnetron are dangerous; avoid contact unless trained.

• Check vents and filters: Ensure all vents are clear and the grease filters (on over-the-range models) are clean. Wash metal filters with hot soapy water and dry thoroughly.
• Allow cooling: If the unit was used heavily, let it cool for 30–60 minutes and try again.
• Inspect cooling fan: Access the internal cooling fan and verify it spins freely and runs during operation. Replace the fan motor if seized or not running.
• Check magnetron thermostat: Locate the thermostat mounted on or near the magnetron. Inspect wiring for burns or loose connections. A thermostat that remains open (no continuity) when cool must be replaced.

Because this area contains the high-voltage system, most users should have a professional handle thermostat or magnetron-related repairs.