LiftMaster 8557 Elite Series 3/4 HP AC Belt Drive Garage Door Opener - Manuel (Page 14)

14
Troubleshooting
Diagnostic Chart
My garage door opener beeps:
The garage door opener can beep for several reasons:
• Garage door opener has been activated through a device or feature such as Timer-to-Close,
garage door monitor or LiftMaster Internet Gateway, see page 4.
• Operating on battery power or the 12Vdc battery needs to be replaced (if applicable), see
page 7 and 11.
My remote control will not activate the garage door:
• Verify the lock feature is not activated on the door control.
• Reprogram the remote control.
• If the remote control will still not activate the door check the diagnostic codes to ensure the
garage door opener is working properly.
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 sensors are properly installed, aligned and free of any obstructions.
DIAGNOSTIC CODE SYMPTOM SOLUTION
Up arrow
Flash(es) Down arrow
Flash(es)
4 1-4
Door is moving stops or reverses. Manually open and close the door. Check for binding or obstructions, such as a broken spring
or door lock, correct as needed. If the door is binding or sticking contact a trained door
systems technician. If door is not binding or sticking attempt to reprogram travel (refer to
page 10).
4 5
Opener runs approximately 6-8", stops and reverses. Communication error to travel module. Check travel module connections, replace travel
module if necessary.
4 6
The garage door opener will not close and the light
bulbs fl ash. Safety sensors are misaligned or were momentarily obstructed. Realign both sensors to
ensure both LEDs are steady and not fl ickering. Make sure nothing is hanging or mounted on
the door that would interrupt the sensor’s path while closing.
My garage door opener light(s) will not turn off when the door is open:
The garage door opener is equipped with a feature that turns the light on when the safety
reversing sensors have been obstructed or when the motion sensor on the door control
detects movement in the garage. These features can be disabled using the door control, see
page 6.
My neighbor’s remote control opens my garage door:
Erase the memory from your garage door opener and reprogram the remote control(s).
My vehicle’s Homelink ® is not programming to my garage door opener:
Depending on the make, model, and year of your vehicle an external adapter may be required.
Visit www.homelink.com for additional information.