Safety: Unplug the microwave. Door switch circuits carry line voltage; avoid touching any exposed wiring when energized.

Check door operation: Open and close the door firmly. Listen for distinct clicks from the door switches. A missing click can indicate a failed or misaligned switch.
Inspect latch hooks: Examine the plastic latch hooks on the door for cracks or wear. If broken, the door will not actuate the switches correctly.
Access door switches: Remove the outer cabinet and control panel to reach the door switch assembly on the latch side.
Check switch alignment: Ensure the switches are firmly mounted and the actuator levers move when the door is opened/closed.
Test switches (with meter): With power disconnected, use a multimeter to check continuity of each door switch according to its NO/NC configuration. Replace any switch that does not change state properly.
Replace damaged parts: Install new Whirlpool door switches or latch assembly as needed. Reassemble and test.

Microwave displays F9 and may not heat or may shut down

Possible Causes