Question about Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+

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Craftsman chain drive is 1994 and has worked fine. Recently door would not close. Manual indicates sensor mis alignment. I have re-aligned and door will work a couple of times or not at all. Receiver green LED is very dim or not lit. I checked voltage at each sensor 6 volts. I also switched sides with sensors same issue only with receiving sensor. Sending eye lights receiver eye doesn't . I don't think it alignment as I have moved receiving sensor around a lot with no long lasting effect. Seems like receiver on some occassions will work for 1 or two cycles of door then green LED will not stay lit. I have read that I may need to sequence the sending sensor to the recieving sensor. Is there a way to isolate to see if the recieiving sensor is bad or if the unit has a bad control board at the unit.

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Problem is probably alignment of sensors. clean off lenses too. you replace them in pairs, but i doubt you need to.

Posted on Jan 15, 2009

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