Robot vacuum shows F4 and stops; may occur when starting or during cleaning, often with no movement.

Safety first: Turn the robot OFF and remove it from the dock. Do not run the robot while inspecting the wheels.

Steps:

• 1. Check for obstructions: Turn the robot upside down. Inspect both drive wheels for hair, threads, or debris wrapped around the axles. Remove debris carefully with tweezers or scissors.
• 2. Test wheel movement: Manually rotate each drive wheel. They should turn smoothly with light resistance and spring up and down freely. If one wheel is stiff or jammed, continue cleaning around the axle and suspension.
• 3. Reset and test: After cleaning, power the robot back on and start a short cleaning cycle on a hard floor. Observe whether both wheels move.
• 4. Advanced check (experienced users): If one wheel still does not move, the drive motor or encoder may be defective. Access usually requires removing the bottom cover. If you proceed, disconnect power, remove the screws, and inspect the wheel module wiring for loose or damaged connectors.

When to call a technician: If F4 persists and a wheel is not driving despite being free of debris, the drive motor assembly or main PCB motor driver is likely faulty. Replacement of the wheel motor module should be done by a qualified technician.