Older garage door opener, 1/2 hp limit switch does not stop door in up position keeps trying and does not shut off?

If you have eliminated the obstruction sensor, I would suggest a few things. Is the door spring set at the proper tension - usually check by releasing the door safety and manually closing/opening the door. It should balance about halfway up/down. Openers have limit switches for travel, if one is incorrectly positioned or faulty, it can cause similar issues. Openers have torque limit controls, if the motor thinks it is working too hard it will stop. Is the door greased and moving freely when you manually tested it for the spring tension? Are the gear sprockets firm and greased?

Sounds like the down limit is out of adjustment. Turn the Down limit switch opposite the direction of the arrow a quarter turn and try again. Repeat until the door stops before hitting the floor then fine tune to shut off at the floor.

When i try opening the garage door from the wall button the door only opens 3 inches or so, then stop but makes several loud clicking noises. I've played around with the travel limits as well as the open force switch but the same thing keeps happening. Any suggestions?

Your door sensors are either bad or need simply to be aligned. They must be pointed at one another to work properly. Each of them has a small light that will be lit when they are pointed correctly.

The thing to do is remove the cover and watch the limit switch assembly. You should be able to see how it is supposed to work and determine what is wrong. A small gear on the end of the shaft turns the limit switch assembly to make contact and turn off the motor in each direction. Something may be broken or out of place. There is also a possibility your logic board is bad especially if you have had electrical storms recently.

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

to tell you how to fix this is tricky your limit switch is not working, if it is a liftmaster, or sears craftsman take the cover down, if it is a older allistar it is a dog limit on the chain, if a genie check the cherry switch in back of operator behind cover.

strange, was going to say eyes not aligned but you say they are. try over-riding by holding down wall pushbutton or jumping from red and white terminals. Did you increase down force. Are limit switch terminals moving, If it hits one, it should go back to other,

The close setting limit switch needs adjusted. Once it is adjusted it should work just fine.

door will not close all the way. will go partway down then reverse itself.