Actually there are many more answers.
Garage door opener sprocket not turning.
Inappropriate size the size and power of the garage door opener must be properly matched with the weight and size of the door.
This repair guide and video show how to replace a chain drive garage door opener gear and sprocket assembly.
What could be causing my garage door opener chain to not move.
So if you suddenly find that the motor on your garage door opener sounds like it s running but the door is not moving checking for worn gears is the first thing you should do.
This speed reduction system also increases the motor torque at the sprocket so that a relatively small motor can easily pull the chain and move the garage door up and down.
How to fix a chain drive garage door when it won t open.
Fortunately the repair is neither difficult nor expensive and it should only take an hour of your time.
Both were something along the lines of either there is no power or the gears are destroyed.
Inside the garage door opener there is going to be a gear reduction system to adapt the motor speed to the chain sprocket speed.
This question is from quora.
Having an automatic door opener in your garage is a great convenience but you have to give the opener and all its parts regular.
As of today 2017 11 08 there were two answers.
This was a craftsman model 139 53976srt.
1 check to make sure the opener is getting power.
If the door is too heavy for the opener the mechanisms that lift the door can wear out quickly.
My wife pushed the door opener a few more times but the door wouldn t move despite the motor responding.
If your garage door opener s motor runs but the chain doesn t move the gear and sprocket assembly might be broken or worn.
I pulled the release on the door and opened it all the way.
You can put the chain back on your automatic garage door opener using a simple adjustment mechanism.
Shredded plastic gears are a common problem with chain driven garage door openers.
I realized parking the car in the garage would be a hassle since i would have the open the door manually again.
This is a video on how to change the gear sprockets in a craftsman garage door opener.