Not tried to read those yet, it is the soldered on quadrature decoder chips that I can make. The PIC17C42 ICs I have yet to attempt.
Dave
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: 09 October 2017 06:48
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Motor stalled.......
If it is the U15 or U16 chip, then David Partridge in the UK has these or can make them.
I have not yet tackled that. These chips are in sockets on the main board and can easily be
pulled out (say with an automotive sharp hook tool) and replaced by the owner.
If it is the motor's encoder element, then, again, I have no experience with that trouble.
In either case, I am surprised the prior owner did not experience the problem and that John, who
just acquired the system, is stuck with this problem from his first experience.
Best of luck,
Michael
On Sun, Oct 8, 2017 at 9:26 PM, brenatlilydale@... [Losmandy_users] <Losmandy_users@...> wrote:
John
Seen this before in DEC and RA, repaired a DEC one not long ago (hope its not same one doubt it).. Unfortunately it's a bad DEC encoder IC. Yes there is a remote possibility its a DEC motor itself or DEC H bridge but I'm pretty sure its as I said.
Upon switch on both motor pinions lock...aka they are applied drive voltages on both sides of their H bridges. Their pinions will have major resistance to movement and be difficult to turn (if you can and do it will log a boot fault in the HC). When you see the HC msg "system boot at xxxx....xx" the Ra pinion starts driving at sidereal rate., the DEC will stay locked resistant to movement and will only move if commanded.
On the system I repaired that had the same symptoms and bad DEC encoder IC (above), the DEC pinion was weak and rotated slowly on pwr on and drove crazy if one of the HC DEC buttons was pressed.
Both Ra/DEC motor encoder ICs U15/16 are firmware installed. Repairer: Rene? (Germany); David Partridge (UK); Michael Herman (USA); Me (Australia); Losmandy (USA)...anyone I miss?
Brendan
--
Michael Herman
mobile: 408 421-1239
email: mherman346@...
[Non-text portions of this message have been removed]
David C. Partridge