trackspot with faulty pan drive

Could also be a bad wire in the harness. If you swap the leads at both the motor end and the logic card end you should be able to determine this.

Hope this helps. :)

Thanks for the response. I did indicate that I swapped the pan and tilt connectors and the problem stayed at the pan output. In other words, with swapped connectors, the tilt motor was erractic, which was connected to the faulty pan output. Meanwhile, the previously erratic pan motor was working fine, with the exception that panning was tilting and tilting was panning, of course.

Yes I understand....you have an erratic pan, and when you swapped the connector to the tilt the problem transferred as well.
This rules out the motor.

You also have replaced the driver chip, so that rules that out as well.

As far as I can tell, what you have not ruled out is the wires going from the main board to the motor. In order to do this you must swap the pan and tilt AT BOTH ENDS (motor end and board/driver end).

If the problem is still with the pan after this, then there is something else wrong with the main board. If the problem transfers to the tilt, you have a bad wiring harness.

Hope this helps. :)

Hi Marty,
the thing that rules out the wire is that I swapped the motor at the main board end and not at the motor end. (I didn`t even see a connector at the motor end!). I guess I wasn't very specific. This leaves a problem on the main board. Any idea what the resistor array from the output of the 74HC373? Some sort of poor mans digital to analog converter to adjust Vref of the driver chip?

Mark