Intelliscope XT10i computer stopped tracking corre

My Intelliscope Computer stopped tracking correctly. After I calibrate it, it's always off by a huge amount even though the computer thinks its working correctly (arrows and actual computer works fine) I've been using the same stars to calibrate it for the 2 years I've had it and tried different stars, positive it's not my error. Must be something with the telescope or base and the wiring? I remember a few months ago the alt. (vertical) direction stopped tracking but I fixed it by tightening the swivel knobs and restarting the calibration. Has anyone had any problems with their Orion Intelliscope Dobs and could recommend any suggestions on what to replace or try to repair??? Thanks!