[AMSAT-BB] Failed G5500 AZ Help

I repaired recently the EL side of the control box. It was working through external control from the CSN SAT controller but it would not work manually. Now the AZ is frozen and won't work manually or through external control. I'm going to check out the roof top connection tomorrow but I'm anticipating the worst like a bad internal rotor pot.

Can any one give me some voltages to check from the controller and what to look for externally at the rotor itself. Perhaps all this is available somewhere online so a pointer to that would be most appreciated.

73 Rick, W2JAZ