Microwave displays E05 and will not start any heating program.

Safety first: Disconnect the microwave from mains power before removing covers.

• Step 1 – Power reset: Leave the microwave unplugged for 5–10 minutes to allow the control board to reset. Plug back in and check if E05 clears.
• Step 2 – Locate cavity sensor: On many AEG microwaves, the cavity temperature sensor (NTC) is mounted on the top or side of the cooking cavity, accessible from behind the outer cover.
• Step 3 – Inspect connections: Check the sensor plug and wiring for loose connections, corrosion, or damage. Reseat the connector firmly on both the sensor and control PCB ends.
• Step 4 – Test sensor: Using a multimeter, measure the resistance of the NTC at room temperature and compare with AEG specifications (commonly in the tens of kΩ). If reading is open, shorted, or far out of range, replace the sensor.
• Step 5 – Control board check: If a known-good sensor is installed and wiring is intact but E05 persists, the control PCB input circuit may be defective and should be replaced by a professional.