superjack actuator
the superjack actuator is a very good actuator, I suspect your position controller is going to the position that is programmed into memory but the actual position of your dish is not on satellite, this usually starts with moving the dish only a little at first to get back on satellite and then more adjustment to get it back as time goes on, I will list the problems that usually occur.
1: screws on the terminal strip rust causing no or intermittent problems
2: plastic nut located at the end of the tube (where the moving part comes out) wears out causing the moving part to slip on the worm gear, to check this: stand on the side of the dish with the actuator, push out on the side of the dish, the dish should be solid and not move
3: reid switch will give problems over time, but usually work or don't work
4: ceramic magnet usually gives no problem unless the glue dries out and the magnet drops of
5: there is an up limit switch and a down limit switch, hardly ever give problems but can get out of adjustment
I would look for the plastic nut to be the problem, that usually means replacing the arm, also, check for a grease fitting on the arm just ahead of the motor, apply grease as needed. hope this helps