Chamberlain 8355 User Manual page 15

Troubleshooting
Diagnostic Chart
DIAGNOSTIC CODE
Up arrow Down arrow
Flash(es) Flash(es)
4
4
4
My garage door opener beeps:
The garage door opener can beep for several reasons:
• Garage door opener has been activated through a device
or feature such as Timer-to-Close, garage door monitor
or LiftMaster Internet Gateway, see page 5.
• Operating on battery power or the 12Vdc battery needs
to be replaced (if applicable), see pages 9 and 13.
My remote control will not activate the garage door:
• Verify the lock feature is not activated on the door
control.
• Reprogram the remote control.
• If the remote control will still not activate the door check
the diagnostic codes to ensure the garage door opener
is working properly.
My door will not close and the light bulbs blink on my
motor unit:
The safety reversing sensor must be connected and
aligned correctly before the garage door opener will move
in the down direction.
• Verify the safety sensors are properly installed, aligned
and free of any obstructions.
SYMPTOM
1-4
Door is moving stops or
reverses.
5
Opener runs approximately
6-8" (15-20 cm), stops and
reverses.
6
The garage door opener
will not close and the light
bulbs fl ash.
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 11).
Communication error to travel module. Check
travel module connections, replace travel module if
necessary.
Safety sensors are misaligned or were momentarily
obstructed. Realign both sensors to ensure both
LEDs are steady and not fl ickering. Make sure
nothing is hanging or mounted on the door that
would interrupt the sensor's path while closing.
My garage door opener light(s) will not turn off when the
door is open:
The garage door opener is equipped with a feature that
turns the light on when the safety reversing sensors have
been obstructed or when the motion sensor on the door
control detects movement in the garage. These features
can be disabled using the door control, see page 7.
My neighbor's remote control opens my garage door:
Erase the memory from your garage door opener and
reprogram the remote control(s).
My vehicle's Homelink
garage door opener:
Depending on the make, model, and year of your vehicle
an external adapter may be required. Visit
www.homelink.com for additional information.
15
SOLUTION
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