On Sat, 09 Sep 2006 11:06:07 GMT, "Viperdoc"
wrote:

I just went through the exact same behavior with my King autopilot. Assuming
the flight director responds to heading bug input, then the most likely
source is the roll servo. There are four drive transistors that can burn
out, and if you are lucky this is the only problem. However, the servo motor
can also be bad, and this can be expensive as well as time consuming if the
replacement is not available. It could also be a combination of both, as was
my case.

Skyhawks don't have a flight director

At least in mine, the roll servo is one large assembly which has the
motor and all the electronics, you can't just swap out any
subcomponants - the entire unit is replaced. At least it has a gear
at the end so you don't need to deal with any of the rigging to
replace it, pop the old one out, stick the new one in, test and return
to service.