Chamberlain WHISPER DRIVE HD900D - Manual (Page 36)

36
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.
Diagnostic Chart
Symptom: One or both of the Indicator lights on the safety reversing 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 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
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: 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: 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.
Motor RPM is not recognized.
Safety reversing sensors
slightly misaligned (dim or
flashing LED).
Door control or wire shorted.
Safety reversing sensors
wire shorted or black/white
wire reversed.
Safety reversing sensors wire
open (broken or disconnected).
1 FLASH
2 FLASHES
3 FLASHES
4 FLASHES
5 FLASHES
OR
Bell Wire
Safety Reversing Sensor
Diagnostics
Located On
Motor Unit
“Learn”
Button LED
or Diagnostic
LED
“Learn” Button
Installed
Safety Reversing
Sensor