Chamberlain GSD series, Installation Manual

Page: 30 / 76

Troubleshooting 29
TROUBLESHOOTING ERROR CODES
Logic 5.0 operators incorporate a self diagnostic feature built into the MAS LED. In addition to indicating when routine maintenance is
due, the MAS LED can be used to troubleshoot problems with the operator.
If the MAS LED on the logic board or 3-button control station is flashing on and off rapidly, the Maintenance Alert System has been
triggered and service is due on the operator. If the MAS LED flashes 2 or more times in a row followed by a pause, an operator error
has occurred. To view the errors, turn the selector dial to DIAG and press the OPEN button. To view the individual error codes (if more
than one exists) press CLOSE. It is possible to have more than one error at a time.
Use the chart below to determine the error.
NOTE: Error codes take priority over normal MAS LED operation. Error codes will repeat on the MAS every 1.5 seconds until cleared.
There may be more than one error present, but only the highest priority will flash. If the highest error is cleared, the next highest will
flash. All errors self-correct when the corrective action is taken. A reset is not needed.
ERROR CODE DESCRIPTION SYMPTOM SOLUTION
1 blink MAS triggered (cycles or months). Normal operation. Reset MAS (page 22).
2 blinks No RPM input during opening or
closing.
The door only responds to
constant pressure commands.
Clutch is slipping, adjust clutch, or verify RPM sensor
connection or replace RPM sensor.
NOTE: To relearn the RPM sensor, move the door with
a constant pressure command. The door will stop once
relearned and normal operation will resume.
3 blinks (MRT) Maximum Run Time has
timed out.
The door stops before reaching
the desired time.
Check the operator for any faults (e.g., bad limit
switch), program the Max Run Timer OR reset to
factory defaults.
4 blinks Obstruction sensed on closing. Operator will reverse to OPEN
position.
Remove obstruction or realign photoelectric sensor.
5 blinks A button is stuck (longer than 2
minutes).
The control station will not
respond.
The control station must be fixed or replaced before it
will be recognized as an input.
6 blinks Invalid option card plugged into
option card receptacles.
Option card will not function
properly.
Refer to accessories page for list of supported option
card(s).
7 blinks LiftMaster Monitored Entrapment
Protection (LMEP) Device faulted
or removed for greater than
2 minutes.
Normal operation (5 second
constant pressure override
required to close).
Cleared when entrapment protection device is cleared
or connected.
8 blinks Brownout Detected - under voltage. Operator will run as long as
enough power is present.
1. Check AC line for voltage.
2. Check transformer secondary
for low voltage.
Too many accessories may be connected to the
transformer.
9 blinks Power board failure. No operator movement. Replace power board.
10 blinks Operator was not in programming
mode when the motor phase
jumper was changed.
The phase will not change. Enter programming mode and move phase jumper to
change phase.
11 blinks Too much voltage supplied to
operator - over voltage.
Operator will run as long as a
component failure does not
occur.
1. Check AC line for voltage.
2. Voltage to be /- 10% of intended voltage.
12 blinks Current sense fault. Motor moves for limited cycles,
then motor no longer moves.
1. Check current sense wiring connection.
2. Cycle operator power after wiring has been
corrected.