GARAGE DOOR OPENS ABOUT 3 INCHES AND STOPS

Check the opening limit dial on the garage door opener unit. You can locate the dial that controls the opening limit on the opener unit and use a flat head screwdriver to turn the dial counter clockwise until the door stops about an inch and a half away from the stop bolt. Then, test the door and make sure it does not slam into the bolt. A video tutorial on how to adjust the opening limit of a Craftsman garage door opener is available on YouTube.

If the above step does not work, check the limit switches on the garage door opener. Most garage door openers have limit switches that control how far the door opens and closes. Improperly adjusting these switches can cause the door to stop halfway. Consult your garage door opener's manual to learn how to adjust the limit switches. Make small adjustments until the door closes fully. Craftsman garage door opening too far and hitting stop bolt easy adjustment (youtube.com)

have a problem which returns every year when outdoor temperatures drop close to freezing. garage door will open only a few inches, then stops. I can close it and try opening it again... same result. After five or six such attempts it typically will open. Interestingly, when I push the switch button mounted on the interior wall of my garage and keep it pushed, the door will open, until I release the button at which point it stops opening.

Check your door sensors.

Check the door springs. One could be broken. Increase he 'up force'. This control is on the rear of the motor unit near where all those white wires go.

Check the door springs and also remove the cover from the motor unit and check the drive gear. The door spring could be broken or the drive gear may be stripped.

The sensors only work when the door is closing.

Check the springs on your garage door. If one is broken, the opener will not have enough power to raise up and it will stop like that.Or the up and down limit settings have gone off or bad.

you need to replace gear when the door is fully closed. then do your tweaking.

You most likely have a broken door spring. Release the door from the opener and try lifting it by hand. Look above the door for the springs.

You have a broken spring on the door. Stop tyring to open door with opener immediately or you will have a broken opener and a broken spring

I would try jumping a wire across the white & red terminal to see if your safety sensors are working Properly! If your door opens you have a loose connection or faulty sensors.