Diagnostic Chart - Merlin MJ3800 Installation And Operating Instructions Manual

"Learn"
Button LED
or Diagnostic
LED
"Learn"
Button

Diagnostic Chart

1 FLASH
Safety reversing sensors
wire open (broken or
disconnected).
OR
2 FLASHES
Safety reversing sensors
wire shorted or black/white
wire reversed.
3 FLASHES
multi-function
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.
9 FLASHES
Cable tension monitor
reversal.
Symptom: One or both of the Indicator lights on the safety reversing sensors do not
glow steady.
• Inspect sensor wires for a short (staple in wire), correct wiring polarity
(black/white wires reversed), broken or disconnected wires, replace/attach as
needed.
• Disconnect all wires from opener.
• Remove sensors from brackets and shorten sensor wires to 30-60mm (1-2")
from back each of sensor.
• Reattach sending eye to opener using shortened wires. If sending eye indicator
light glows steadily, attach the receiving eye.
• Align sensors, if the indicator lights glow replace the wires for the sensors. If the
sensor indicator lights do not light, replace the safety reversing sensors.
Symptom: LED is not lit on multi-function door control.
• Inspect Multi-Function Door Control/wires for a short (staple in wire), replace as
needed.
• Disconnect wires at multi-function door control, touch wires together. If opener
activates, replace multi-function door control.
• If opener does not activate, disconnect multi-function door control wires from
opener. Momentarily short across red and white terminals with jumper wire. If
opener activates, replace multi-function 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.
• Verify door track is firmly secured to wall and does not move.
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 unit's APE
(Absolute Positioning Encoder) may need to be replaced, for details contact your
Chamberlain reseller.
Symptom: Door reverses while closing.
• Check for possible door obstructions and remove.
• Check that the cable tension monitor is properly connected to the opener.
• Replace the cable tension monitor.
Installed
Safety Reversing
Sensor
Your door opener is programmed with self-diagnostic
capabilities. The "Learn" button/diagnostic LED will flash a
number of times then pause signifying it has found a
potential issue. Consult Diagnostic Chart below.
21