Help: Celestron AVX mount playing up

[Spacer (Shar)]

So I bought a used avx mount locally in Sydney. The seller said that the controller is damaged but assured that the mount works correctly. I believed him and bought the mount.

Bought a new controller and the issue doesn't seem to have been fixed.

Old controller: with the controller that came with the mount, once plugged in, it only lights up but doesn't display any text. Pressing buttons make no difference (pressing buttons too hard makes the controller lcd flicker!)

New controller: Powers on, display initial verifying package and comes to life. Then if I try to slew, the slewing starts but keeps going and doesn't stop even after releasing the button, unless I switch off the mount. On other occasions, it slews for a fraction of a second and then stops, hand controller restarts and then nothing works. I have tried Aux1 and Aux2 ports as well, makes no difference.

Can anyone help me with some directions please? I am happy to take it to a professional for repair if anyone can recommend one in Sydney. Thanks.

[Rob-Minchinbury (Rob)]

Bintel should be able to do a service and let you know what's wrong.

I emailed them last year when a cheap Celestron mount motor (not purchased from them) was damaged, sent a photo of the motor and a description of the issue, and via email they knew which replacement was needed.

Unfortunately the motor wouldn't be shipped to them for 6 months so I never did take it in to be repaired. I was impressed with their remote diagnostic based on a blurry photo, and their ability to identify exactly which motor replacement was needed (it isn't listed on Celestron's support site).
I ended up buying a 2nd hand mount just for the motor, and did the swapper myself.

1st hand controller could be several problems including a short circuit in the aux ports which sends enough power to light the screen but not enough for the processor to perform the initialisation.
The hand controller could have a partially fried circuit due to that power issue, or the LCD or its cable could be damaged.
If you have the USB or RS232 cable you could maybe turn it all on, press the buttons that would normally be required to finish the boot up, then take control via PC - if it works, it suggests only the LCD is damaged.

New controller - upgraded models maybe(?) use less power? The slewing issue could again be due to short circuit in the aux ports, or a loose pin (unusual to affect both ports though). When it continues slewing can you tap the button again and make it stop?

If you open the mount casing and inspect the cabling and circuit board where the aux ports connect you might see some corrosion, sign of heat damage (black dots or soot), or a loose cable.

I'd be keeping the 2nd hand controller unplugged as much as possible ... you don't want to fry that if the aux board is faulty.

Final thing to check would be your power source - is it providing sufficient and sustained power?