Discussion about the Korg PolySix synthesizer

Hi Andy

well, in normal mode I can select every button on 371 and every relative led lights up.

The example you did was clear, when I press "Bank C" and "Program 2" on the KLM-371 IC3 /3Q (pin 11) goes from 5V to 0v, and IC4 /2Q (pin 14) does the same 

Again, if I press Bank Program A-1, pin1 on IC2 and pin1 on IC4 goes from 5V to 0V.


But when I put the dumy resistor on the power supply board to follow the reset procedure, no one LED goes on, except for

"ARPEGGIO - HOLD - CHORD MEMORY - UNISON -POLY

but sometime some of this LED's doesn't go on...it's a quite crazy
thing, despite all everything sounds good in normal mode...

Cheers

Aniello



p.s: what do you mean when you say that IC3 on KLM-371 is part of MG routing switch? 
Doesn't IC3 work to power on MANUAL and WRITE LED's and to put 5V into "INA1-2" and "INA3-4" on IC2 IC4 and IC5?





--- In PolySix@yahoogroups.com, Andrew Jury <andy@...> wrote:
>
> 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@...> 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
> > 
> 
> 
> 
> [Non-text portions of this message have been removed]
>