[amsat-bb] 5400B Rotor problem Help

I could use some trouble shooting tips for my rotor. The azimuth part tho mechanically still rotates through 360 degrees the indication both on the control box and my computer only shows 180 deg travel. The indicator moves continously while the rotor is moving but at only half the speed it normally travels showing only 180 deg swing for 360 on the rotor. Since i get the same reading on both my pc and the control box I assume the problem is either in the rotor or the wireing from the rotor. I could use some suggestions. Bill KB2RC