Your jammed garage door can be caused by something as simple as an obstruction in the track.
Garage door opener locked up.
Unplug the garage door opener.
Here is a link that might be useful.
This can be a quick fix by identifying the object and then removing it.
Ever forget your keys to the house or even lost your garage door remote.
How to lock your garage door.
Lock the release lever.
With some garage openers a feature exists that allows you to put the opener in lock mode.
Check to see if anything a shovel broom etc fell and is now stuck in the track that is causing it to be lodged.
This is related to the up limit switch.
Find a manual for trouble shooting.
Use a padlock to lock the garage door from the inside.
Locate the force adjustment dials.
Remove the release lever cord.
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.
Try making small adjustments.
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.
Every garage door opener has an emergency release that disconnects the door from the opener.
Some use a wedge to hold the gap open.
T his is a pretty uncommon problem but one that can happen after you ve first installed your garage door opener.
Garage door locked from the outside.
Use a padlock to lock the track.
Once locked a normal press of the button will not activate the door.
These things can leave you at the mercy of a lo.
You can activate this feature by holding down the button on your keypad for several seconds.
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.
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.
By pushing the door inward to create a gap at the top a crook can insert a wire hook and fish for the release.
This video will show you how for most garage door openers including liftmaster chamberlain sears.
Disable the release lever.
If your garage door opener is locked check the wall control it may be set to vacation mode.
It means you will have to find the model number but it helps.
Use a zip tie to secure the garage door in place.
Without it you wouldn t be able to open the door when the opener is on the fritz.
Slip a c clamp through the track.