The only thing i can think is that maybe the sensor has gone bad but they can be a pain to trouble shoot without one of their specialists.
Garage door opener locked up.
Ever forget your keys to the house or even lost your garage door remote.
I have used it several times.
Garage door locked from the outside.
Find a manual for trouble shooting.
Use a padlock to lock the garage door from the inside.
Check to see if anything a shovel broom etc fell and is now stuck in the track that is causing it to be lodged.
Unplug the garage door opener.
This can be a quick fix by identifying the object and then removing it.
To open it up all you need to do is thread a coat hanger or hooked piece of wire through the top of the door and open the emergency latch which can also be done by the rope many emergency latches.
Keep the remote in the house.
Slip a c clamp through the track.
You can activate this feature by holding down the button on your keypad for several seconds.
They can be found at the back panel of your craftsman garage door opener to increase the open force turn the open force dial about 1 4 of a full turn similarly to increase the close force turn the close force about 1 4 of a full turn operate your garage door.
This is related to the up limit switch.
It means you will have to find the model number but it helps.
If your garage door opener is locked check the wall control it may be set to vacation mode.
Your jammed garage door can be caused by something as simple as an obstruction in the track.
Use a padlock to lock the track.
Once locked a normal press of the button will not activate the door.
This video will show you how for most garage door openers including liftmaster chamberlain sears.
It s important to get this switch at just the right distance from the motor so that the door is able to close all the way but the motor also knows to stop running.
How to lock your garage door.
Locate the force adjustment dials.
These things can leave you at the mercy of a lo.
Without it you wouldn t be able to open the door when the opener is on the fritz.
Lock the release lever.
Lodged garage door track.
Use a zip tie to secure the garage door in place.
With some garage openers a feature exists that allows you to put the opener in lock mode.
T his is a pretty uncommon problem but one that can happen after you ve first installed your garage door opener.
Remove the release lever cord.
Every garage door opener has an emergency release that disconnects the door from the opener.
Disable the release lever.
Try making small adjustments.