What I fear is the case with too many pivot techs is that they really don't understand how the electrical system works in a pivot. I can't tell you how many time I've had to 'splain that the "secret" is that the end tower moves and the rest of the machine plays catch-up. The only kink is that the timer in the second-to-outside tower shuts down the machine if the second-to-last tower doesn't move frequently enough, which means that the last tower is stuck and spinning it's wheels.

Once I hit upon this "big picture" of how pivots worked, debugging pivot problems became pud-simple.