Microwave stops heating shortly after start; display shows E02 and beeps.

Safety warning: Always unplug the microwave before inspection. Do not remove the outer cabinet or touch internal high-voltage components unless you are trained; the capacitor can store lethal voltage.

External checks:

• Ensure the microwave has adequate ventilation: at least the clearance specified in the SMEG manual on sides, top, and rear. Move it away from walls or cabinets if necessary.
• Inspect all external vents and grilles for dust, grease, or obstructions. Clean with a soft brush and vacuum.
• Verify that the cooling fan can be heard running when the microwave is operating. A silent unit (when it previously made fan noise) may indicate a failed fan motor.

Reset attempt:

• Unplug the microwave for 15–20 minutes to allow thermal cut-outs to cool and reset (if they are auto-reset types).
• Plug back in and test with a cup of water on a low power setting. If E02 reappears quickly, stop using the unit.

Advanced checks (technician recommended):

• Check the magnetron cooling fan motor for proper operation and replace if seized or noisy.
• Test the magnetron thermal cut-out and cavity thermal cut-out for continuity; replace any open device with the correct SMEG-rated part.
• If the magnetron shows signs of overheating or arcing, it may need replacement.

Do not bypass safety devices. If you are not experienced with microwave HV systems, contact a professional technician.