I came across this message board and this topic Tangent electronics for Celestron telescopes. I recently purchased a Celestron Ultima 8. I was fully prepared and expecting some problems, even to the extent of not being able to use the clock drive! It didn't bother me, the unit in question was in great condition with perfect optics.

It's the 1989 model, with the internal sealed lead acid batteries. They were super easy to replace, as expected, and as I researched prior to the telescope purchase. $15 US for 2 new Hawker Cyclon Lead Acid "D" cells, 2 volt, 2.5 AH. You can find these on batterymart.com. I got them from the local specialty battery shop.

I replaced the batteries. Now they charged up fine, and a voltmeter fonfirmed this.

The problem now is, simply, the AC motor will not operate. The motor is a "Synchron" 110v AC, 3watt bla blaa bla and it works fine. It's the electronics board, and the quartz locked inverter which I suspect.

Measuring the output voltage from the board, to the motor, read a fluctuating value, from 8 to 11 volts AC...

Now comes the fun part. Try finding a replacement electronics board from Tangent, for a 1989 model?! =D HA! Well, I guess I'll try.

Again, this comes as no real surprise or dissapointment to me. I expected this kind of thing.

I would like to remind all reading this, of the somewhat obvious: Electronics break down eventually!!! I've long since come to the conclusion that electronics are best avoided as much as possible. Nevermind. This Ultima 8 is a great SCT telescope, and if the worst comes to the worst, I won't be able to track objects in the sky. Boo hoo!

I'll try calling this "Tangent" electronics place, and see what they say. I WILL post an update of what happens. For the sake of all those who find this through a search engine, like I did. There are few resources for these old Celestron telescopes!