Diagnostic Chart - Chamberlain LiftMaster Elite Security+ 3800PC Owner's Manual

Operation
Your garage door opener is programmed with self-diagnostic capabilities. The diagnostic
LED will fl ash a number of times, then pause, signifying it has found a potential issue.
Consult Diagnostic Chart below.
Installed
Safety Reversing
Sensor

Diagnostic Chart

1 FLASH
Safety reversing sensors wire open
(broken or disconnected)
OR
2 FLASHES
Safety reversing sensors wire shorted or
black/white wire reversed
3 FLASHES
Door control or wire shorted
4 FLASHES
Safety reversing sensors slightly
misaligned (dim or flashing LED)
5 FLASHES
Motor RPM is not recognized
9 FLASHES
Cable tension monitor reversal
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 polarity (black/white
wires reversed), broken or disconnected wires, replace/attach as needed.
• Disconnect all wires from back of garage door opener.
• Remove sensors from brackets and shorten sensor wires to 1-2 ft. (30-60 cm) from
back each of sensor.
• Reattach sending eye to garage door opener using shortened wires. If sending eye
indicator light glows steadily, attach the receiving eye.
• 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.
SYMPTOM: The door doesn't activate from the door control.
• Inspect door control/wires for a short (staple in wire), replace as needed.
• Disconnect wires at door control, touch wires together. If garage door opener activates,
replace door control.
• If garage door opener does not activate, disconnect door control wires from garage
door opener. Momentarily short across red and white terminals with jumper wire. If
garage door opener 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 fi rmly secured to wall and does not move.
SYMPTOM: Door travels 2-3 inches and stops.
• Reprogram limits and forces. See Adjustment section.
• If the motor unit continues to travel 2-3 inches, check the travel module connection or
replace the travel module.
SYMPTOM: No movement, motor runs 2-3 seconds.
• Reconnect the emergency release.
• Motor may need to be replaced.
Symptom: Door reverses while closing.
• Check for possible door obstructions and remove.
• Check that the cable tension monitor is properly connected to the opener.
• Replace the cable tension monitor.
29
Garage Door Opener
"Learn"
Button LED
or Diagnostic
LED
"Learn"
Button
Safety Reversing Sensor