Craftsman Garage Door Opener Acting Wierd

[BD]

I have a 1/2 HP Craftsman GDO that is about 3 years old. All of a sudden the door will now only open about 12 to 18 inches; the lights do not flash at this point. If I press the button (on the wall or the remote) the door will go down and then (usually) return back up to the 12 or 18 inch height. HOWEVER, if I block the beam with my foot before it starts going back up, it will return continuing to the fully open position and the lights will flash. Any ideas? Thanks, Bill

[Mr. Tool]

1. Check the beam alignment.

1. Make sure something on the back of the door isn't intruding into the beam.

2. Check the load setting on the motor, maybe increase it a bit.

1. Check the tracks to see if they are all stable and aren't missing a piece.

Weird problem.

Hope this helps,

The "Tool"