1 check to make sure the opener is getting power.
Garage door opener chain pin fell off.
If the light does not come on then check the power by plugging a light or fan into the socket.
Simply push the button and see if the light comes on.
Pull down the trolley cord to release the trolley from the chain arm and lower the door by hand.
This plastic pin has two tabs that you have to pull gently to the side to allow the pin to slide out.
The small gear is held on by a plastic pin that goes thru the shaft.
Keep it propped open while you fix the chain.
Thread the nut s facing the door clockwise until it meets the bracket then release the chain.
Grasp the chain 1 foot from where it connects to the end of the threaded chain anchor.
If you are outside the door when this occurs you will need some assistance to move the door manually.
If you are not confident in your ability to diagnose the problem call a local garage door service company.
Pull the chain toward the garage door and hold it in position.
Sprocket is at the end of the opener rail closest to the garage door opening.
Maybe it is as simple as a gfi or circuit breaker flipping.
If you find that your garage door opener chain falls off the track on which it has been placed you will need to put it back up and then tighten the chain to stop this happening in the future.
Press down on the chain with your finger.
The chain drive module has a gear on the bottom that has to be removed both to take out the old module and before installing the new module.
My chain fell off my garage door its an xtreme garage door opener and it looks like the link that held a cable on the other side of the gear chain fell off.
Place a stepladder near the motor and unplug the power cord for the motor from the electrical.