20
DIAGNOSTIC CHART
Possible limit switch
error on start up.
Possible RPM sensor
failure. Unplug to reset.
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 dis-
connected).
1 FLASH
2 FLASHES
3 FLASHES
4 FLASHES
5 FLASHES
6 FLASHES
OR
System failure
10 to 15 FLASHES
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).
