Oven display shows F40, oven may not recognize door position correctly.

Safety first: Turn off power at the breaker before working around the door switch.

• Locate door switch: The switch is usually mounted behind the front frame where the door closes, or integrated into the latch mechanism.
• Check mechanical action: Open and close the door while observing the switch actuator. Ensure it is fully depressed when the door is closed. Adjust the latch or strike if necessary.
• Test switch continuity: Disconnect the switch and measure continuity while pressing and releasing the actuator. Replace the switch if it does not change state reliably.
• Inspect wiring: Follow the wires from the switch to the control board. Repair any broken or loose connections.
• Re-test: Restore power and verify that the oven now detects door open/closed correctly and that F40 is cleared.