DIAGNOSTIC CHART
1 FLASH
Safety reversing sensors
wire open (broken or dis-
connected).
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
Possible RPM sensor
failure. Unplug to reset.
6 FLASHES
Possible limit switch
error on start up.
10 to 15 FLASHES
System failure
Symptom: One or both of the indicator lights on the IR Beams are not on
steadily.
• Inspect sensor wires for an electrical short (eg. staple in wire), correct wiring polar-
ity (black/white wires reversed), broken or disconnected wires, replace/attach as
needed.
• Disconnect all wires from the opener.
• Remove beams from brackets and shorten sensor wires to 30-60mm (1-2") from
back of each sensor.
• Re-attach sending eye to opener using shortened wires. If sending eye indicator
light glows steadily, attach the receiving eye.
• Align beams. If the indicator lights glow, replace the wires for the beams. If the sen-
sor indicator lights do not light up, replace the IR Beams.
Symptom: LED is not lit on door control.
• Check polarity of the wire connection to the opener.
• Inspect door control/wires for an electrical short (eg. staple in wire), replace as need-
ed.
• Disconnect wires at door control, touch wires together. If opener activates, replace
door control.
• If opener does not activate, disconnect door control wires from opener. Momentarily
short across red and white terminals with jumper wire. If 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.
Symptom: The RPM Sensor = Short travel 150-200mm (6-8").
• Unplug unit to reset. Try to operate opener. Check diagnostic code.
• If it is still flashing 5 times and opener moves 150-200mm (6-8"), the RPM sensor
may need to be replaced, for details contact your Chamberlain Merlin Professional
Dealer.
Symptom: Door will not open or close
• Turn the power off. Wait 10 seconds.
• Turn power back on. If opener fails to operate correctly after resetting, contact
your Chamberlain Merlin Professional Dealer.
Symptom: Opener will not open or close the door
• Turn the power off. Wait 10 seconds.
• Turn power back on. If opener fails to operate correctly after resetting, contact your
Chamberlain Merlin Professional Dealer.
(report the number of flashes as the fault reference).
20