[amsat-bb] G5400B rotor problem

I have an old 5400B that I use at a summer location. I use another old fox delta serial control interface that emulate GS-232. It has developed a strange problem with the AZ rotor that seems to occur when it reaches the extreme S (past E) where it tends to freeze. The only way to unfreeze it and gain control again is to shut the control box off for a short time and then it will run fine manually or under control by SATPC32. I’m guessing there may be some thermal device inside the rotor itself that is exceeding a limit and needs to cool down. I’d love to hear some suggestions on what the problem might be.

Tnx Rick, W2JAZ