Chamberlain C870 Owner's Manual page 39

Troubleshooting
Diagnostic Chart
Your garage door opener is programmed with self-diagnostic capabilities. The UP and DOWN arrows on the garage door opener flash the diagnostic codes.
DIAGNOSTIC CODE
Up Arrow Down Arrow
Flash(es) Flash(es)
1 1
1 2
1 3
1 4
1 5
1 6
2 1-5
3 2
3 3
4 1-4
4 5
SYMPTOM
The garage door opener will not close and the light bulbs flash.
The garage door opener will not close and the light bulbs flash.
The door control will not function.
The garage door opener will not close and the light bulbs flash.
Door moves 6-8" (15-20 cm) stops or reverses.
No movement, only a single click.
Opener hums for 1-2 seconds no movement.
Door coasts after it has come to a complete stop.
No movement, or sound.
Unable to set the travel or retain position.
The battery status LED is constantly flashing green.
Door is moving stops or reverses.
Opener runs approximately 6-8" (15-20 cm), stops and reverses. Communication error to travel module. Check travel module connections, replace travel module if
SOLUTION
Safety reversing sensors are not installed, connected, or wires may be cut. Inspect sensor wires for a
disconnected or cut wire.
There is a short or reversed wire for the safety reversing sensors. Inspect safety sensor wire at all staple
and connection points, replace wire or correct as needed.
The wires for the door control are shorted or the door control is faulty. Inspect door control wires at all
staple and connection points, replace wire or correct as needed.
Safety reversing sensors are misaligned or were momentarily obstructed. Realign both sensors to
ensure both LEDs are steady and not flickering. Make sure nothing is hanging or mounted on the door
that would interrupt the sensor's path while closing.
Manually open and close the door. Check for binding or obstructions, such as a broken spring or door
lock, correct as needed. Check wiring connections at travel module and at the logic board. Replace
travel module if necessary.
Manually open and close the door. Check for binding or obstructions, such as a broken spring or door
lock, correct as needed. Replace logic board if necessary.
Manually open and close the door. Check for binding or obstructions, such as a broken spring or door
lock, correct as needed. Replace motor if necessary.
Program travel to coasting position or have door balanced by a trained door systems technician.
Replace logic board.
Check travel module for proper assembly, replace if necessary.
Battery backup charging circuit error, replace the logic board.
Manually open and close the door. Check for binding or obstructions, such as a broken spring or door
lock, correct as needed. If the door is binding or sticking contact a trained door systems technician. If
door is not binding or sticking attempt to reprogram travel (refer to page 29).
necessary.
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