Question about liftmaster Chamberlain Garage Door Opener Transmitter 300MC

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Lift-Master garage door opener stopped working

I have a Lift-Master 1/2 hp garage door opener that was installed when the house was built, circa 1997. It's worked fine for 12 years. Now when I push the wall button to open the garage door, the opener box clicks once and then a green light blinks 5 times in succession, then there
s a wait, and then 5 again.The opener doesn't make any other sound but the single click when you push in the button, followed by the 5 blinks of the green light.

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I tried everything on mine which had the same problem. I cleaned the the circuit board with a toothbrush to remove some of the excess grease which had flung off the cogs then tried unplugging and plugging back in again and it worked. Mind you I did try unplugging it before several times which didn't work until I cleaned the circuit board. Hope this helps.

Posted on Apr 25, 2013

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This might be VERY basic, but this happened to me.

Do you have attic space just above the garage? Could there be a heavy box on top of some wires? Those wires seem to be very sensitive & as soon as I moved the boxes off of some wires that looked like phone wires it WORKED like normal.

Posted on Aug 14, 2009

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The motor will probably need rewinding.
Professional job. Don't forget to take the condensor with the motor.
Or alternatively, if money isn't a problem,, get somebody out to look at it.
There ya go:)

Posted on Jul 27, 2009

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