Chamberlain 248739 - Manual (Page 35)

35
6. My motor unit hums briefl y:
• 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.
• 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.
• Decrease the UP travel by turning the UP Travel
adjustment screw 2 full turns away from the arrow.
• 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.
Having a Problem? (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 fl ashes on the motor unit
then refer to the Diagnostic Chart on the following
page.
2. My remotes will not activate the door:
• Verify your Multi-Function Door Control is not
blinking. If it is blinking, deactivate the Lock Mode
following the instructions for Using the
Multi-Function Door Control.
• Reprogram remotes following the programming
instructions. Refer to Programming.
• If remote will still not activate your door, check
diagnostic LED for fl ashes on motor unit then refer
to Diagnostic Chart on the following page.
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, Set the force.
4. My door reverses for no apparent reason after fully
closing and touching the fl oor: 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, Adjust the UP and
DOWN Travel Limits. Decrease down travel by
turning down limit adjustment screw clockwise.
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.
Bell Wire
Safety Reversing Sensor
“Learn”
Button
LED or
Diagnostic
LED
Sending Eye Safety
Reversing Sensor
(Amber Indicator Light) Receiving Eye Safety
Reversing Sensor
(Green Indicator Light)
Trolley
1-1/4"
(3.18 cm)