Craftsman 139.53993D - Manual (Page 34)

Diagnostic Chart
Safety reversing sensors
wire open (broken or
disconnected).
OR
Safety reversing sensors
wire shorted or
black/white wire
reversed.
Door control or
wire shorted.
Safety reversing sensors
slightly misaligned
(dim or flashing LED).
Motor overheated or
possible RPM sensor
failure. Unplug to reset.
Motor Circuit Failure.
Replace Receiver
Logic Board.
issue. Consult Diagnostic Chart below.
Symptom: One or both of the Indicator lights on the safety sensors do
not glow steady.
• Inspect sensor wires for a short (staple in wire), correct wiring poiarity (biack/white
wires reversed), broken or disconnected wires, repiace/attach as needed.
• Disconnect ail wires from back of motor unit.
• Remove sensors from brackets and shorten sensor wires to 1 -2 ft (30-60 cm) from
back each of sensor.
• Reattach sending eye to motor unit using shortened wires. If sending eye indicator
light giows steadily, attach the receiving eye.
• Aiign sensors, if the indicator iights glow replace the wires for the sensors. If the
sensor indicator lights do not light, replace the safety sensors.
Symptom: LED is not lit on door control.
• Inspect door control/wires for a short (staple in wire), replace as needed.
• Disconnect wires at door control, touch wires together. If motor unit activates,
replace door control.
• 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.
Symptom: Sending indicator light glows steadily, receiving indicator light is
dim or flashing.
• Realign receiving eye sensor, clean lens and secure brackets.
• Verify door track is firmly secured to wall and does not move.
Symptom: Motor has over heated; the motor unit does not operate;
RPM Sensor = Short travel 6-8" (15-20 cm).
• Unplug unit to reset. Try to operate motor unit, check diagnostic code.
• If it is still flashing 5 times and motor unit moves 6-8" (15-20 cm), replace RPM
sensor.
• 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.
Symptom: Motor unit doesn’t operate.
• Replace logic board because motor rarely fails.
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