Discussion about the Korg PolySix synthesizer

Hi Aniello,

Well it sounds like you have been diligent in your repairs. I just has to go
back and remind myself what your problems were (it¹s been a while now!). Are
you sure that all the LEDs are working / driven? I.e. if you press bank
selection C2 then on the KLM-371 IC3 /3Q should go low and IC4 /2Q should
also do the same. Test them all in turn to verify. Look at the schematic and
all will become clear. Also, I have had a couple of Polysix in the lab with
open circuit LEDs, so don¹t get caught out with that one! Can you confirm
that the bistable latches we talked about above work as per design?

IC3 is part of the MG routing switch, so I don¹t think this is the problem.

Cheers,
Andy


On 19/09/2010 18:13, "aniello iaccarino" <ani.bliss@gmail.com> wrote:

>  
>  
>  
>    
> 
> Hi Andy, thanks for your reply.
> Sorry I wrote 366 instead of 367 :)
> 
> I checked all the PIO on the CN10 but this time I pressed the relatives
> buttons during the measurement, for example:
> 
> I put the scope on P10 and the level was 0, then I press 1-5-A-Manual and I
> can see the two logic states on the oscilloscope. I did this for every P on
> CN10 and all works fine.
> 
> So the problem should be on the 367. The board was repaired for the usual acid
> problem. And the original blue socket too was changed whit one with this kind
> of pin-holes
> 
> http://rocky.digikey.com/weblib/Mill-Max/Web%20Photos/117-93-640-41-005000.jpg
> 
> the board was cleaned and the broken tracks wire-jumpered.
> I tested all the PIO directly connected from  to the CPU to the CN and I can't
> find any interruption.
> 
> I have to say the synth has not any particular problem, every parameter works
> good. But I'd like to understand the cause of this problem (a firend of mine
> has this same problem too).
> 
> Do you think the problem could be caused by a malfunction of IC3 on 371?
> I see P26 and P27 are directly connected on this IC.
> 
> Aniello
> 



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