I moved in this house 18 months ago, it has 1/2 HP garage door from Sears/Craftsman. The remote control looks like http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=00953778000

It has been working fine all these times, but it suddenly stopped working 2 days ago.

Here are my terminologies, so you understand what I was walking about:

Opener: the remote control I place in my car, which has 3 rectangle buttons.

Two Receivers: Mounted bottom of two sides of garage door frame

Controler: component on the garage door motor, which has a button (someone called learn button), a green light which lights up when you press the learn button, and 3 terminals with all sorts wires attaches to the.

Wall Unit: mounted on the wall in garage which use to open/close garage door from Garage.

1) I can use wall unit to open/close garage door, so the motor works.

2) Press button on opener, the green light on opener lights up, so the battery in the opener works, it is a brand new battery I put in yesterday.

3) Close door from garage, then immediately standing below the garage door, the door open up again, with garage door light blinking, Could I say the receivers also works?

4) This may not related, but it is worth to metion, there are 2 garage door lights on both side of control unit on the top of garage ceiling. A month ago, one of the light doesn't work, I thought it was a bad light bub, so I changed a new light bub, but it still didn't work. Since the door still works, so I didn't pay much attention. This broken light is on the same side as control unit while all 3 terminals and the learn button are.

5) I did open the opener, there is no switch on the opener.

6) I also unplug the power, and replug in after 5 minutes. It still doesn't work.

My question,

1) If it turns out tht I had a bad opener, can I just go buy another opener (from Sears/Craftsman), can it be easily programed?

2) Do you where I can download Sears/Craftsman opener user manual?