[Radrich]

Hello this is my first post. Sorry if I am not in the right place. I am trying to fix my garage door opener. I did a replacement of the main sprocket gear and now when I push the button it only opens a out a foot then it immediately closes. What can I do pleas help

 

[joecaption]

Pull on the rope to reliece the opener in the closed position.
Now by hand open and close the door.
Should be easy to open with one hand and should be able to stop in any position and have stay.

 

[iamrfixit]

This is the chamberlain/liftmaster style opener?

Check the RPM sensor, the black segmented wheel on the end of the worm drive shaft. Make sure it is pushed all the way on the shaft so that the segmented rim actually splits the pickups of the sensor board. Also make sure the wires are plugged into the sensor board correctly, not disconnected or off by one pin.

This is the best pic I could find
http://www.amazon.com/gp/customer-media/product-gallery/B00023RTD6?ie=UTF8&index=1