I have a craftsman 3/4 hp garage door that will not go down, sometimes it goes down about 2 inches then back up and flashes 10 times. It will go all the way down if I hold the wall button until it reaches the end of its travel.

I’ve checked all the tracks for any obstructions, I’ve unplugged the thing for 24 hours, cleaned the sensor lenses with alcohol, and that’s when I noticed that the receiver (green LED light) doesn’t appear to be working anymore, no matter how I position the two sensors the green light never turns on and there is absolutely nothing blocking the sensors.

So, can I just replace the sensor or is there an issue somewhere else in the system?

  • my garage door opener does that when the lock button on the wall control (wired control) is activated
    – jsotola
    Commented Oct 22, 2018 at 23:50
  • No, unfortunately that doesn’t seem to make any difference. The light on the wall control blinks when locked and stays solid when unlocked, but didn’t seem to affect the sensor lights at all. Thank you. Commented Oct 23, 2018 at 0:06

1 Answer 1


Check your garage door opener manual for a trouble-shooting procedure which may help figure out where the problem really is. It certainly could be just the sensor. Having had a bizarrely behaving garage door which turned out to be the main "computer" board in the opener, I'd want to try and check that the sensor was getting whatever it needed to operate correctly before I'd assume that the sensor was the cause of the sensor not working and bought a new one. If, for instance, the main unit is not supplying power to the sensor, replacing the sensor won't fix it. Your manual may provide some procedures to test/isolate the problem.

More generally, my advice (despite the fact that I did replace that main board for a successful repair) is always to consider the age of the unit and the price of a replacement. Parts are often not returnable and don't have any warranty, while a whole new unit comes with a whole new warranty. In my case I bet that the board, at about half the cost of the relatively new opener would do it, as I knew there had been a nearby lightning strike. With an older unit, I'd lean heavily to replacement to avoid replacing so many parts trying to solve the problem that I'd have spent less for a complete new opener.

To be clear, I have no idea where your actual problem is, but it could be:

  • The sending unit
  • The receiving sensor unit
  • Or the main unit powering both units and reading the sensor output
  • Or the wires connecting them may be broken.

If your garage has mice as most do, that last one might be the first one to check.

  • +1 for the wires connecting them. This was the problem in my garage, the road salt from the car had corroded the wires near the garage floor. No power, no sensor.
    – IronEagle
    Commented Oct 23, 2018 at 5:56
  • I don’t know if the wires broke when I was pulling them out or if it was broken before hand but one of the staples was really snug and while trying to get it out I broke one of the wires. So I stripped the wires spliced them together and wah lah everything is working again. I’m still not sure why after 5 years the wires suddenly broke but that doesn’t matter anymore. Thanks for the ideas and help everyone. Commented Oct 23, 2018 at 19:11
  • The fact that it did not work, then worked after you spliced them together indicates that it was broken beforehand.
    – Ecnerwal
    Commented Oct 25, 2018 at 16:40

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