Display shows F12; door moves a few inches then stops; repeated attempts cause same behavior.

Safety first: Disconnect power before adjusting or replacing limit components.

• 1. Locate limit assembly: On many Linear models, mechanical limit switches or cams are mounted on the rail or near the motor. Identify the open and close limit devices.
• 2. Inspect cams and actuators: Ensure the cams that trigger the switches are tight on the shaft and positioned correctly. Tighten set screws if loose.
• 3. Check wiring harness: Follow the small harness from the limit switches or encoder to the control board. Look for pinched, cut, or unplugged connectors. Reseat connectors firmly.
• 4. Test switches: With power off, use a multimeter to verify that each limit switch opens and closes when actuated. Replace any switch that does not change state.
• 5. Replace encoder/limit assembly: If the encoder wheel is cracked or the sensor is damaged, replace the entire travel sensor assembly with a Linear OEM part.
• 6. Reprogram limits: After replacement, follow the manual to set or learn the open and close limits, then test full travel.