Oven displays F9, often when trying to use self-clean or when door is supposed to lock/unlock.

Safety first: Disconnect power before accessing the door lock mechanism. Surfaces may be hot after a self-clean attempt.

• Check door movement: Verify the oven door opens and closes smoothly. If it is jammed or misaligned, inspect hinges and latch for obstructions or bent parts.
• Listen for lock motor: When starting self-clean (with power restored), listen for the lock motor running. No sound may indicate a failed lock motor or no power to it.
• Access lock assembly: Remove the top panel or rear panel (depending on model) to access the door lock motor and switch assembly. Inspect for broken plastic parts, disconnected rods, or burnt wiring.
• Test switches: With power OFF, use a multimeter to check continuity of the lock switches when the latch is manually moved to locked and unlocked positions. Replace the lock assembly if switches do not change state.
• Replace lock assembly: If the motor is seized or switches are faulty, replace the complete door lock motor and latch assembly.