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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: how can we Gemini owners prevent such damage in the first place?

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
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