Sears 139.18847 - Manual (Page 35)

Having a Problem?
(continued)
Situation Probable Cause & Solution
The door reverses for
no apparent reason
and opener lights
don't blink: 1. Is something obstructing the door? Pull the red emergency release handle. Operate
the door manually. If it is unbalanced or binding, call for professional garage door
service.
2. Clear any ice or snow from the garage floor area where the door closes.
3. Review the force adjustment procedures on page 29.
4. If door reverses in the fully closed position, decrease the travel limits (page 28).
Repeat safety reverse test after adjustments to force or travel limits. The need
for occasional adjustment of the force and limit settings is normal. Weather
conditions in particular can affect door travel.
The door reverses for
no apparent reason
and opener lights
blink for 5 seconds
after reversing:
The opener light:
. . . doesn't turn on:
Replace the light bulbs (75 watts maximum). Use a standard neck garage door opener
bulb if regular bulb burns out.
. . . doesn't turn off:
Is the Light feature on? Turn it off.
The opener strains or
maximum force is
needed to operate
door: The door may be out of balance or the springs are broken. Close the door and use the
emergency release to disconnect the trolley. Open and close the door manually. A properly
balanced door will stay in any point of travel while being supported entirely by its springs. If it
does not, disconnect the opener and call a professional garage door serviceman.
Do not
increase the force to operate the opener.
The opener motor
hums briefly, then
won't work: 1. The garage door springs are broken. See above.
2. If the problem occurs on the first operation of the opener, door may be locked. Disable
the door lock. If the chain was removed and reinstalled, the motor may be out of phase.
Remove the chain; cycle the motor to the down position. Observe the drive sprocket.
When it turns in a clockwise direction and stops in the down position, reinstall the chain.
Repeat the safety reverse test after the adjustment is complete.
The opener won't
operate due to
power failure: 1. Use the emergency release to disconnect the trolley. The door can be opened and closed
manually. When the power is restored, press the Door Control push button and trolley will
automatically reconnect (unless trolley is in lockout position.) See page 32.
2. The Outside Trolley Release accessory (for use on garages with no service door)
disconnects the trolley from outside the garage in case of power failure.
The chain droops
or sags: It is normal for the chain to droop slightly in the closed door position. Use the
emergency release to disconnect the trolley. If the chain returns to normal height when
the trolley is disengaged and the door reverses on a one-inch board, no adjustments
are needed (see page 11).
35
The door opens but
won't close:
Check the safety reversing sensor. Remove any obstruction or align the receiving eye.
See page 23.
1. If the opener lights blink, check the safety reversing sensor. See page 23.
2. If the opener lights do not blink and it is a new installation, check the down force.
See Adjustment Step 2, page 29. For an existing installation, see below.
Repeat the safety reverse test after the adjustment is complete.