Chamberlain 8500 Manual page 17

Installation
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. 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.
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.
Sending sensor - amber LED
IF THE AMBER LED ON THE SENDING SENSOR IS NOT GLOWING:
• Make sure there is power to the garage door opener.
• Make sure the sensor wire is not shorted/broken.
• Make sure the sensor has been wired correctly: white wires to white terminal and
white/black wires to grey terminal.
IF THE GREEN LED ON THE RECEIVING SENSOR IS NOT GLOWING:
• Make sure the sensor wire is not shorted/broken.
• Make sure the sensors are aligned.
ENSURE THE DOOR CONTROL IS WIRED CORRECTLY
The yellow command LED and the red learn LED on the door control will blink quickly for
up to 5 minutes as the door control recharges. When the door control is operational, the
yellow command LED will glow steadily.
Light Beam Protection Area
Receiving sensor - green LED
17
Sticker on back