Craftsman garage door openers
My craftsman garage door opener, model #139.53660SRT1, moves sometimes a few inches or a few feet, stops, reverses. This happens with the door connected or not. The sensors are alined properly, they never blink but stay green. I made sure the rail was tight, the door when free moves in the track easily. I have adjusted the up/down screw setting numerous times to get the proper force, (following the manual instructions). The motor gets hot the more I move the door, but the problem is the same if motor is hot or cold. The RPM sensor had two tabs that were not completely pushed in, corrected that, but still the same problem. Help.