Azimuth motor gearing problem
I also purchased a used Meade ETX-70, only to find it had the same problem with the rotation axis motor running but no movement. After removing the bottom cover, I found the motor w/worm gear would not contact the main rotation gear. I solved the problem but purchasing a small 3/8x3/4x.032 spring that I had to custom fit to hold the motor w/worm gear against the rotation gear. Take caution not to have the spring apply to much pressure or it will cause to much drag.
To gain access, remove the bottom round cover(it will just pop off).
Then use a small .05 allen wrench to remove the set screw in the horizonal chrome lock. The chrome lock fits over a 1/2" bolt. By removing this bolt you will remove the washer/bearing assembly. After removing this, you will see a nylon nut, use a 11/16 socket to remove. Becareful, it is a fine thread and you don't want to cross thread it!
After you remove this, you will be able to remove the bottom housing, which will expose the motor and gear. You should be able to see what I am referring and where to place the spring.
If you can make it this far, then you should be able to install the spring. I used a little small dab of Gorilla glue to hold it in place, since the spring will have enough constant tension to keep it from moving.
I'm not sure if this was a design flaw, but I got no help from the Techs at Meade, only that they would upgrade to a ETX-80 for $149.99 plus shipping.
Hope this helps....... Read More At : ETX-70 (240 x 70mm) Telescope...