Having A Problem? (Troubleshooting) - Chamberlain Liftmaster Security+ 3900PLD Owner's Manual

HAVING A PROBLEM?
(TROUBLESHOOTING)
1. The operator doesn't operate from either the Door
Control or the remote control:
• Does the operator have electric power? Plug a lamp
into the outlet. If it doesn't light, check the fuse box
or the circuit breaker. (Some outlets are controlled by
a wall switch.)
• Is there a build-up of ice or snow under the door?
The door may be frozen to the ground. Remove any
restriction.
• The door spring may be broken. Have it replaced
(see page 3 for reference).
2. Operator operates from the remote, but not from
the Single Button Control Station:
• Are the wiring connections correct? Review
Installation Step 5.
3. The door operates from the Single Button Control
Station, but not from the remote control:
• Program the operator to match the remote control
code. (Refer to instructions on the motor unit panel.)
Repeat with all Remotes.
4. The remote control has short range:
• Check to be sure the antenna on the side or back
panel of operator extends fully downward.
• Some installations may have shorter range due to a
metal door, foil backed insulation, or metal siding.
5. The door opens and closes by itself:
• Be sure that all remote control push buttons are off.
• Remove the bell wire from the door control terminals
and operate from the remote only. If this solves the
problem, the single button control station is faulty
(replace), or there is an intermittent short on the wire
between the control console and the motor unit.
• Clear memory and re-program all remote controls.
6. The door doesn't open completely:
• Is something obstructing the door? Is it out of
balance, or are the springs broken? Remove the
obstruction or repair the door.
7. The door opens but won't close:
• Check cable tension monitor (see installation step 4).
• Check the safety reversing sensor. See Installation
Step 9.
• See Adjustment Step 2. For an existing installation,
see below.
Repeat the safety reverse test after the adjustment
is complete.
8. The door reverses for no apparent reason:
• Check cable tension monitor (see installation step 4).
• Is something obstructing the door? Pull the
emergency release handle. Operate the door
manually. If it is unbalanced or binding, call a trained
door systems technician.
• Clear any ice or snow from the floor area where the
door closes.
• Review Adjustment Step 2.
Repeat safety reverse test after adjustments.
9. The door reverses for no apparent reason:
• Check the safety reversing sensor. Remove any
obstruction or align the receiving eye. See Installation
Step 9.
10. The operator strains to operate door:
• The door may be out of balance or the springs may
be broken. Close the door and use the emergency
release handle to disconnect the door. 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
operator and call a trained door systems technician.
11. The operator motor hums briefly, then won't work:
• The door springs may be broken. See above.
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