Microwave shows E7 and may shut down mid-cycle; cooling fan may run at high speed.

Safety: Unplug the microwave before inspection.

Ventilation and fan checks:

• Ensure that the microwave's vents (top, rear, or sides depending on model) are not blocked by cabinets, wall, or items on top.
• For over-the-range models, verify that the exhaust fan is running when cooking. If it is not, the fan motor or control may be faulty.
• Clean any grease filters and intake screens that may be clogged.

Sensor inspection (qualified DIYers):

• Remove the outer cabinet to locate the exhaust temperature sensor / thermostat near the top or rear of the unit.
• Inspect wiring for damage or loose connections.
• Test the sensor or thermostat with a multimeter for continuity/resistance according to specifications. Replace if open, shorted, or out of range.

If E7 persists: The control board's temperature sensing circuit may be defective. Replacement of the electronic control board is recommended and should be done by a professional.