how can we Gemini owners prevent such damage in the first place?
The most common cause of these problems is (as I understand it) mis-connecting the motor DIN plugs. I know they are polarized but I¡¯m told it¡¯s still possible to mis-plug them.
Dave
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: 10 October 2017 15:00
To: Losmandy_users@...
Subject: RE: [Losmandy_users] Re: Motor stalled.......
I have fortunately not found Gemini units with this damage - yet. I cannot yet do that repair, as I have not yet developed the programming kit to make these replacements, but I will look into that.
Better:
Can anyone say what is causing these chips to fail?
Is there a simple preventative measure owners can take to avoid such damage?
Best,
Michael
On Oct 10, 2017 4:33 AM, "'David C. Partridge' david.partridge@... [Losmandy_users]" <Losmandy_users@...> wrote:
The decoder ICs U15 and U16 are no longer obtainable from Losmandy or Aveox. However they are just AFT16V8BQL-15SU PLDs which need to be programmed.
I have the jedec file to program them if you have a suitable programmer and SOIC adapter.
The two ICs are the SOIC-20 parts at the upper right edge of the G-1 PCB. You'll need hot air soldering kit or "Chip-Quik" to remove them.
If you aren't comfortable doing that then either Michael Hermann or I can repair for you (I'd suggest Michael if you are in USA as I live in the UK).
You can test the shaft encoder with the motor removed from the mount and without the Gemini controller.
Use a 5V supply, ground to pin 1, +5V to pin 4 of the HEDS-9100. You can then turn the motor pinion by hand and observe the signals on pins 3 and 5 HED-9100. If you only get a signal on one or neither, then replace the encoder.
Clear skies
Dave Partridge
[Non-text portions of this message have been removed]
David C. Partridge