Question about liftmaster Chamberlain Garage Door Opener Transmitter 300MC

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One of the sensors on the side of the door is yellow, the main unit hanging in the garage has a yellow light, and it only closes if we hold the button down. otherwise light blinks and it kicks back, like something is in the way

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Senor are obstructed, gently wipe off the lenz, look for any dust, cob webs or loose wires.
make sure the eyes see each other ( look for the lites on the side) one green and one yellow, tap on to make sure they do not flicker, move them around until you have a strong steady lite and then tighten down. this should solve your problem

Posted on Oct 07, 2010

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1 Answer

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