Did you just install the opener? If so did you follow the instructions? It looks like it is out of adjustment but with you clicking the remote it is impossible to tell what is actually happening.

Thanks for your reply.
The opener has been there for long time. It is screw drive type opener. On the rail assembly, there is an inner trolley (also called rack) and outer trolley. The problem I'm having is inner trolley moves fine, but once outer trolley is engaged, it would not move, making noise, as seen 26sec into the video. Then after disengaged outer trolley, the rack/inner trolley moves back and forth smoothly.

I didn't connect the door, so just try to isolate the problem from the garage door.

Thanks, Alice

Here is a link that might be useful: video is here at Youtube-Garage opener problem

If you look at the parts breakdown under rail assembly parts in your owners manual you can see a part called a rack and one called the sprocket coupling. One of these is bad. Your opener is also opening too far and the trolley is jamming against the motor unit. This could be what caused your problem. At any rate you will need to remove the t-rail to inspect those two parts.

Thanks, I do see "rack" and "sprocket coupling" in the manual as in the link below.

One more question, is it difficult to remove the T-rail and put it back on? it seems just few screws at the end of the wall, is there any thing special we need to pay attention to?

Thanks,

Alice

http://teknuw.com/wordpress/wp-content/uploads/2011/02/Liftmaster_2110.pdf

Here is a link that might be useful: manual is here

Okay there are those screws at the wall and if you look at page 6 of your manual you will see you have to remove 2 bolts and nuts and then the rail will slide off.

Thanks very much for your suggestion, I'll take apart the rail assembly and post the update. Thanks again,

Alice

Fred777,email address is :fred_kreyer@yahoo.com,Subject :Garage door opener problem. I'm having problems with my garage door openers,the garage door openers open the garage door from inside of the house,but with the garage door closed and you are outside of the house and you use the garage door openers they will not open the garage door. I would like some ideas on what I can do.Thank you very much for your feedbacks, Fred777