LiftMaster 3850 3850 Elite Series Manual - Page 31

Having a Problem (Troubleshooting) NOTE: Always unplug battery prior to troubleshooting. 1. My door will not close and the light bulbs blink on my motor unit: The safety reversing sensor must be connected and aligned correctly before the garage door opener will move in the down direction. • Verify the safety reversing sensors are properly installed, aligned and free of any obstructions. Refer to Installation Step 10: Install The Protector System®. • Check diagnostic LED for flashes on the motor unit then refer to the Diagnostic Chart on the following page. 2. My remotes will not activate the door: • Verify your Smart Control Panel® does not display "Lock Mode." If it does, deactivate the Lock Mode following the instructions for Using the Door Control. • Reprogram remotes following the programming instructions. Refer to Programming. • If remote will still not activate your door, check diagnostic LED for flashes on motor unit then refer to Diagnostic Chart on the following page. Bell Wire Diagnostics Located On Motor Unit Safety Reversing Sensor Sending Eye Safety Reversing Sensor (Amber Indicator Light) "Learn" Button LED or Diagnostic LED Receiving Eye Safety Reversing Sensor (Green Indicator Light) 3. My door reverses for no apparent reason: Repeat safety reverse test after adjustments to force or travel limits. The need for occasional adjustment for the force and limit settings is normal. Weather conditions in particular can affect door travel. • Manually check door for balance or any binding problems. • Refer to Adjustment Step 2, Setting the force. • Run the motor unit from the remote control or door control. The trolley should travel towards the door and stop. If the trolley re-engages with the door, pull the Emergency Release Rope to disengage. Trolley 4. My door reverses for no apparent reason after fully closing and touching the floor: Repeat safety reverse test after adjustments to force or travel limits. The need for occasional adjustment for the force and limit settings is normal. Weather conditions in particular can affect door travel. • Refer to Adjustment Step 1, Program the Travel Limits. Decrease down travel. 5. My lights will not turn off when door is open: • The garage door opener is equipped with a security light feature. This feature activates the light on when the safety reversing sensor beam has been obstructed. Refer to Operation section; Using the Wall-Mounted Door Control, Light Feature. 6. My motor unit hums briefly: • First verify that the trolley is against the stop bolt. • Release the door from the opener by pulling the Emergency Release Rope. • Manually bring the door to a closed position. • Loosen the belt by adjusting the outer nut 4 to 5 turns. This relieves the tension. 1-1/4" (3.18 cm) • Re-Tighten the outer nut until the trolley spring is approximately 1-1/4" (3.18 cm) in length. • If the trolley does not move away from the bolt, repeat the steps above. 7. If battery status LED is not lit properly: • Check battery connections. 8. My garage door opener beeps: • A solid LED with beep, sounding approximately every 2 seconds, indicates the motor unit is activating the door and is operating off of the battery. • A flashing LED with beep, sounding every 30 seconds, indicates battery is low. • If a red LED remains on when the power is restored, and is accompanied by a beep sounding every 30 seconds, replace the battery. 31