An electric garage door can become stuck in the open position for several reasons.
Garage door opener stuck in down position.
Over time the bottom of one of the rails worked itself a little loose and i found that the vibration of the door coming down would rattle the rail and disturb or misalign the sensor to the point that it would read an interruption and the door would reopen.
Check the door s electric eye.
Turn the power back on and the door should open and close normally.
Shut off the power to the garage door opener.
The chain part of the loop on the side of the rail is a little loose hanging down probably about an inch or so.
Your jammed garage door can be caused by something as simple as an obstruction in the track.
When the opener button is pushed there is a hum for a second but that s all.
The metal string part of the loop on the other side of the rail is tight.
If your garage door gets stuck when opening this may be why.
Check to see if anything a shovel broom etc fell and is now stuck in the track that is causing it to be lodged.
Lodged garage door track.
This can be a quick fix by identifying the object and then removing it.
Use a screwdriver to tighten the wire.
Garage door is off the track in some circumstances it is possible for the rollers that move the garage door up and down to jump the track.
Because of the potential danger of broken parts you should inspect the garage door for damage before attempting to close it.
When you know there is no damage to the door you can close the garage door by disconnecting the door from the electric opener.