My Lift master door opener goes part of the way down then stops if i hit the opener button again it will go down another foot or so then it stops again and so on until it goes all the way down

SOURCE: Garage door goes a quarter way up.

If the wall station is flashing the lock button is on Push and hold the lock button for 2 sec. and release. The light should be solid(not flashing) For you door opening part of the way: If you have a Chraftsman/Liftmaster:
 1.Check to see if the door is running correctly.
  A. Run the door down and pull the emergency release. See if the door will run easily by itself.
    1. If it runs hard by hand try lubricating the rollers and hinges with silicone spray or some form of lubricant (not WD 40)
    2. If the door is heavy and falls back to the ground, you probably have a spring issue (either broken or needs more tension) in this case call a professional door repair company in your area.
  B. If the door runs fine then check the up and  down force on your operator (the box that hangs from the ceiling). If the light bulb(s) on your operator are on the front and/or back, the force adjustment screw is on the back of the operator. If the lights are on the sides of the operator then the force adjustment screw is on the right side (looking from the back of the operator and facing  the garage door). Turn the light blue adjustment screw with the up arrow to a higher number.
C. If this does not solve your problem the top bushing could be going out of your operator. Open the case and see if a lot of black filings are on the top of the big gear. If so the gear assy. will have to be replaced part # 41C4220A

SOURCE: door opener only opens a little bit

i have run into this problem before this might be of some help
check your track and see if someone has greased it if so get a rag and solvent and remove all grease from roller track this track is never to be lubricated in the summer grease thins and lets dooor move but in winter grase hardens and acts like glue binding door past set limits.

SOURCE: Lift-Master garage door opener stopped working

The motor will probably need rewinding.
Professional job. Don't forget to take the condensor with the motor.
Or alternatively, if money isn't a problem,, get somebody out to look at it.
There ya go:)

SOURCE: My Sears Craftman garage door opener closes about

If the main light is flashing 10 times when the door reverses it is a door sensor problem. One may have been bumped so that they no longer point at one another. Make sure the small light on each sensor is lit and not flickering. If this isn't the case you might need to increase the down force a little. The control is on the back panel near where all those white wires go. Increase it about 1/4 turn and try.

SOURCE: Lift master garage door opener.

power is on, the door will go up about 12-16 inches and stop, but with help it will go all the way up,but !!!!!! when i hit the button to make it go back down it only moves about 12 inches whats up with this!!!!!!!!!!!!!!!!!!!!