Microwave displays E9 and the interior light stays on even when the door is closed; unit will not start.

Safety: Unplug the microwave before removing the cabinet or control panel.

Steps:

• 1. Check door operation: Open and close the door firmly. Ensure it latches securely and is not misaligned or warped.
• 2. Inspect door switches: Access the door switch assembly near the latch. Identify the monitor switch (often with different wiring than the primary/secondary). Test with a multimeter for proper open/closed operation as the door is opened and closed.
• 3. Replace faulty switch: If the monitor switch does not change state correctly, replace it with the correct Avanti door monitor switch. Ensure the actuator is properly engaged by the latch.
• 4. Check wiring: Inspect for pinched or shorted wires around the door latch area. Repair any damaged insulation and secure wiring away from moving parts.
• 5. Control reset: After repairs, reassemble, plug in, and test. If E9 persists with good switches and wiring, the control board may require replacement.