Troubleshooting a DMD-1 controller

I think the mount is an old (I know for sure it's old) Superpolaris or just plain Polaris mount & came with a Celestron telescope. The controller is a hand held DMD-1. The RA drive control stopped functioning.

1. The dec. drive works fine. Therefore, the controller is getting power. Works off of 6 AA batteries.

2. When I plug the dec. drive cable into the RA drive socket on the telescope and press a button, the RA drive will slew. So, I conclude that the RA drive motor is ok and the problem is upstream from the motor.

3. Plugging the RA drive cable into the dec. drive motor and pushing a button does nothing. Conclusion, either the RA cable is bad or RA controller electronics is bad.

4. The hardwired RA cable (hardwired into the DMD-1 controller) has a 5 pin plug that goes to the telescope drive motor.

Anyone know where I can find a schematic diagram for the DMD-1 controller? Or, does anyone know what signals and voltages to expect at the RA cable, 5 pin connector?

Russ Schnitzer

Try calling Celestron and talk to someone in tech support.According to an old S.A.A. thread(1999) someone else with problems was sent a schematic by Celestron.They did not have any parts but were able to provide a schematic.The party in question was able to find the part he needed somewhere else.Teletrade(listed on Astromart sponser page)is a good source for parts.Good luck!