HELP! Dead Scope

I got a similar effect when I switched an autostar between an EXT70 and and LXD75.

It took a reset and reselecting the correct mount to fix the problem.

Hope it works out for you.

Try and get a hold of another autostar controller and test it again.
My LX would sometimes go into full slew in DEC for no apparent reason. I cleaned all yhe connection points but in the end bought a new controller and never had any further problems.

Hi Paul,
Is that the same scope with the cap blown on the motor drive? If so then can I suggest that you get that cap replaced first. Normally we use those capactiors as "bulk" caps to keep the supply rails smooth around the board. If it is blown then any spike/inconsistencies caused by motors/psu etc will get through to the microcontroller and can upset it. I recently fixed a C11 for a clubmate which had a few psu problems but the one which kept it from running was that the eeprom portion of both microcontrollers had been corrupted. Once I reprogrammed these it all came back to life.

If you don't fix the caps - it'll probably just happen again.

My PM offer still stands and I'd put my name in the pot for the mount(don't need the tripod) if you decide to split it up for sale.

John

Just spotted your PM - reply sent.

Hi all

I managed to attempt another align today, I went through the controllers menu until I got to telescopes, I looked for the LX models and found none, ETX scopes, DS models sure, no LX though.

Anyway, I tried the alignment, the same thing happened, the dec motor is fine, the RA kept rotating until the power was disconnected.

I checked the Meade website about an upgrade but I need a connector kit which I don't have.

I think, as I have had offers on various parts, I will break it up, as I'm no longer into observing I can put the cash to a better use.

Thanks for the advice.

Paul

Hi Paul,
Don't forget the links I sent to you. It is highly probable that it is just that encoder feedback that needs adjustment. Drive runaway is very common in all position controlled driven systems (CNC machines etc) when the encoder feedback is bad. I had a radar gimble a few years ago that pinched its encoder cable with the same effect. In this case though it used the same encoder for speed control and it spun at full tilt -boy could that move :laugh:

Is there anyone in Paul's area that has access to an oscilloscope? The adjustment is not difficult to do and could give him back his scope.

Paul, if you have no luck locally, let me know and we'll try to organise something between us to get it done.

John