Chamberlain 248730 - Manual (Page 36)

35
Operation
Diagnostic Chart
Your garage door opener is programmed with
self-diagnostic capabilities. The “Learn”
button/diagnostic LED will flash a number of times
then pause signifying it has found a potential issue.
Consult Diagnostic Chart below.
Installed
Safety Reversing
Sensor
“Learn”
Button
Safety Reversing
Sensor
Bell Wire
Diagnostics Located
on Motor Unit
LED or
Diagnostic
LED
1 Flash
Safety reversing
sensors wire open
(broken or
disconnected).
OR
2 Flashes
Safety reversing
sensors wire shorted
or black/white wire
reversed.
Symptom: One or both of the Indicator lights on the safety
reversing sensors do not glow steady.
l Inspect sensor wires for a short (staple in wire), correct
wiring polarity (black/ white wires reversed), broken or
disconnected wires, replace/attach as needed.
l Disconnect all wires from back of motor unit.
l Remove sensors from brackets and shorten sensor wires
to 1-2 ft. (30-60 cm) from back each of sensor.
l Reattach sending eye to motor unit using shortened wires.
If sending eye indicator light glows steadily, attach the
receiving eye.
l Align sensors, if the indicator lights glow replace the wires
for the sensors. If the sensor indicator lights do not light,
replace the safety reversing sensors.
3 Flashes
Door control or wire
shorted.
Symptom: LED is not lit on door control.
l Inspect door control/wires for a short (staple in wire),
replace as needed.
l Disconnect wires at door control, touch wires together. If
motor unit activates,
replace door control.
l If motor unit does not activate, disconnect door control
wires from motor unit.
Momentarily short across red and white terminals with
jumper wire. If motor unit
activates, replace door control wires.
4 Flashes
Safety reversing
sensors slightly
misaligned (dim or
flashing LED).
Symptom: Sending indicator light glows steadily, receiving
indicator light is dim or flashing.
l Realign receiving eye sensor, clean lens and secure
brackets.
l Verify door track is firmly secured to wall and does not
move.
5 Flashes
Motor overheated or
possible RPM sensor
failure. Unplug to
reset.
Symptom: Motor has over heated; the motor unit does not
operate or trolley is stuck on stop bolt = Motor unit hums briefly;
RPM Sensor = Short travel 6-8" (15-20 cm).
l Unplug unit to reset. Try to operate motor unit, check
diagnostic code.
l If it is still flashing 5 times and motor unit moves 6-8" (15-20
cm), replace RPM sensor.
l If motor unit doesn’t operate, motor unit is overheated. Wait
30 minutes and retry.
If motor unit still will not operate replace logic board.
6 Flashes
Motor Circuit Failure.
Replace Receiver
Logic Board.
Symptom: Motor unit doesn’t operate.
l Replace logic board because motor rarely fails.