Microwave beeps and shows E05; cooking stops unexpectedly, often after a short time.

Safety first: Unplug the microwave before accessing any internal components. Avoid contact with the high-voltage section.

User-level steps:

• 1. Power cycle: Unplug for 5 minutes, then plug back in and test. Temporary glitches can sometimes clear.
• 2. Avoid empty runs: Never run the microwave empty; this can cause abnormal temperature readings and sensor stress.

Advanced steps (for experienced DIYers):

• 3. Locate the cavity sensor: On many Westinghouse models, the temperature sensor (thermistor) is mounted on the top or side of the cooking cavity, accessible after removing the outer cover.
• 4. Inspect wiring: Check the sensor harness for damage, pinched wires, or loose connectors. Reseat the connector on both the sensor and control board.
• 5. Test sensor resistance: Disconnect the sensor and measure its resistance at room temperature. Compare to the service manual spec for your model. Replace if open, shorted, or out of range.

If E05 persists after sensor replacement, the main control board may be faulty and should be evaluated by a technician.