Matthew,
The encoder is what causes the motor unit fault. There
is a light emitting diode that the encoder must spin
near. When the encoder blocks the light the computer
sees it as a turn of so many degrees at the motor. If
the diode or encoder are not working correctly the
computer doesn't see the motor spin and gives the
message.
Most of the time the encoder wheel itself is dirty or
has grease blocking the windows in between the flats.
Rarely but possible the diode will go out. It gives
off ultra-violet light so don't look for it, you can't
see it without certain filters.
Clean and align the encoder wheel first and see if
that fixes it.
The diodes can be had at Radio Shack I am told but I
have not gone and looked for them.
Jerry in Arizona


--- matthew_w100 <matthewwilliams@...>
wrote:

> Can anyone tell me what ACTUALLY initiates the motor
> unit failure
> message? My azimuth motor is locked in this state,
> after I had it
> completely apart to mend a broken motor carrier
> (cheap plastic broken,
> but unfortunately outside warranty). The motor is
> definitely not
> stuck; it spins happily forwards and back when power
> is applied
> directly. There is a tiny little optical encoder on
> the motorshaft;
> could this be at fault? And what is the other
> electrical plug into
> the carrier for? It holds three wires (blue, green
> and yellow) but
> they don't seem to actually connect to anything on
> the motor.
>
> Thanks,
>
> Matthew
>
>




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