The sensors can be easily disrupted. Sometimes their electronics break down, sometimes they break with a crash.
If your sensor fails, you can replace it yourself instead of calling for service. Materials
sensor for your model.
You can see how it can be done practically from the video.
Sensors can be found in a retailer, or in places such as amazon and ebay at a price of $ 25-35.
Be sure to turn off the power before changing the sensor.
If you write a comment at the point where you have problems, we will be happy to help.
You can watch another video from this link as a different method.
craftsman garage door opener sensor replacement