[TowerTalk] Yaesu G800SA Problem

[Bob Pack, NX5M]

I have a G800SA that turns one of the 15m yagis that has decided to only 
rotate about half of what it should.  
>From 180 degrees it will rotate clockwise and stop cold at about 50 degrees.
I will not rotate past 50 degrees on around to the east.
I have not gone up the tower to check it out yet but thought that perhaps 
someone here has had the same experience and might be able to tell me what 
the problem might be.

73,
Bob NX5M