LiftMaster 8550C Mode D'emploi page 22

Power
2
Ensure the Safety Reversing Sensors are aligned
The door will not close if the sensors have not been
installed and aligned correctly.
When the light beam is obstructed or misaligned while
the door is closing, the door will reverse and the
garage door opener lights will flash ten times. If the
door is already open, it will not close. The sensors can
be aligned by loosening the wing nuts, aligning the
sensors, and tightening the wing nuts.
.
IF THE AMBER LED ON THE SENDING SENSOR IS NOT GLOWING:
Make sure there is
power to the garage
door opener.
3
Ensure the Door Control is wired correctly
If the door control has been installed and wired correctly a message will display on the screen.
2.1
Check to make sure the LEDs in both sensors are glowing steadily. The LEDs in both sensors will glow steadily if they are aligned and
wired correctly.
Make sure the Make sure the sensor has been wired
sensor wire is not
correctly: white wires to white terminal
shorted/broken.
and white/black wires to grey terminal.
Amber LED
(invisible light beam)
E S N D N I G E S N S O R
IF THE GREEN LED ON THE RECEIVING SENSOR IS NOT GLOWING:
Make sure the sensor wire is
not shorted/broken.
22
If the receiving sensor is in
direct sunlight, switch it with
sending sensor so it is on the
opposite side of the door.
Green LED
E R E C V I N I G E S N S O R
Make sure the sensors are aligned.