Chamberlain 3265CM, 3266CM 1 FLASH, 2 FLASHES, 3 FLASHES, FLASHES, Diagnostic Chart, FLASHES, FLASHES, Logic Board, wire shorted, disconnected), not glow steady, Door control or

Bell Wire

	Diagnostics
	Located On
	Motor Unit	Installed
		Installed
		Safety Reversing
		Sensor
	LED or
	Diagnostic
	LED
	“Learn”	Your garage door opener is programmed with self-diagnostic
Safety Reversing Sensor	Button	capabilities. The “Learn” button/diagnostic LED will flash a
		number of times then pause signifying it has found a potential
Diagnostic Chart		issue. Consult Diagnostic Chart below.
Diagnostic Chart
1 FLASH	Symptom: One or both of the Indicator lights on the safety sensors do
Safety reversing sensors	not glow steady.
Safety reversing sensors	• Inspect sensor wires for a short (staple in wire), correct wiring polarity
wire open (broken or
wire open (broken or	(black/white wires reversed), broken or disconnected wires, replace/attach
disconnected).
disconnected).	as needed.
OR	as needed.
OR	• Disconnect all wires from back of motor unit.
	• Disconnect all wires from back of motor unit.
2 FLASHES	• Remove sensors from brackets and shorten sensor wires to 1-2 ft. (30-60 cm)
	from back each of sensor.
Safety reversing sensors	• Reattach sending eye to motor unit using shortened wires. If sending eye
wire shorted or black/	indicator light glows steadily, attach the receiving eye.
white wire reversed.	• Align sensors, if the indicator lights glow replace the wires for the sensors. If
	the sensor indicator lights do not light, replace the safety sensors.
3 FLASHES	Symptom: LED is not lit on door control.
Door control or	• Inspect door control/wires for a short (staple in wire), replace as needed.
Door control or	• Disconnect wires at door control, touch wires together. If motor unit activates,
wire shorted.
	replace door control.

•If motor unit does not activate, disconnect door control wires from motor unit. Momentarily short across red and white terminals with jumper wire. If motor unit activates, replace door control wires.

4	FLASHES	Symptom: Sending indicator light glows steadily, receiving indicator light
Safety reversing sensors		is dim or flashing.
Safety reversing sensors		• Realign receiving eye sensor, clean lens and secure brackets.
slightly misaligned
slightly misaligned		• Verify door track is firmly secured to wall and does not move.
(dim or flashing LED).

5	FLASHES	Symptom: Motor has over heated; the motor unit does not operate or
Motor overheated or		trolley is stuck on stop bolt = Motor unit hums briefly; RPM Sensor =
Motor overheated or		Short travel 6-8" (15-20 cm).
possible RPM sensor		Short travel 6-8" (15-20 cm).
possible RPM sensor		• Unplug unit to reset. Try to operate motor unit, check diagnostic code.
failure. Unplug to reset.
failure. Unplug to reset.		• If it is still flashing 5 times and motor unit moves 6-8" (15-20 cm), replace

		RPM sensor.
		• If motor unit doesn’t operate, motor unit is overheated. Wait 30 minutes and
		retry. If motor unit still will not operate replace logic board.

6	FLASHES	Symptom: Motor unit doesn’t operate.
Motor Circuit Failure.		• Replace logic board because motor rarely fails.
Replace Receiver
Logic Board.
Logic Board.		30
		30