Discussion about the Korg PolySix synthesizer

It sounds like you've reached the point where a scope is necessary 
for any meaningful work -- this will help you zero in on the problem 
areas, and is a much better idea than just replacing ICs at random.
(The Polysix circuit boards aren't that robust to begin with;  they 
don't stand up to too much desoldering & resoldering.  Add to that 
the weakening caused by battery damage, and it becomes obvious that 
random replacing of components may not work out so well.)

If you can borrow an oscilloscope, view the outputs of IC31 (pins 3, 
6, 8 and 11) -- should see strong, consistent signals.  Look for the 
same on IC30 (same pin numbers) -- these two ICs distribute the data 
lines DO0 - DO7 to all the circuitry.  Look at the connectors CN06 
and CN10 -- see if all "D" and "P" signals are present.  If they're 
not, this could be the cause of your problem.

As stated before, there isn't just one IC that controls the panel -- 
it's a matrix of data lines that work together to control a number of things.

Another thought:  have you checked the wires that are soldered to the 
front panel, right side?

~G
At 08:01 PM 11/18/2007, you wrote:

>well, i replaced all the bad traces, put in a socket for the IC31
>and a new IC31 that had never been heated/soldered into the socket,
>established all continuities, and my problem is still
>there....The 'write' LED and the LED's for program #4and 6 and D
>stay lit. i can also switch between #1,2,3, but i get no response
>above #4....Does anyone have an idea if another chip is at fault that
>controls these LED's? if its not IC31? --- In
><mailto:PolySix%40yahoogroups.com>PolySix@yahoogroups.com, klosmon 
><klosmon@...> wrote:
> >
> > At 01:05 PM 11/14/2007, you wrote:
> >
> > >My thoughts exactly, ive already ordered the IC AND a socket... (
> > >parts cost under $2) that way i dont have to heat the IC at
> > >all....But I still wonder what the IC 31 does, and if it controls
> > >the patch selection, etc.
> >
> >
> > Well, I answered that question a few days ago -- see message #1692.
> > That answer contains good and true information, based on having
> > repaired about forty polysixes. Not sure what I could add...
> > ~G
> >
> >
> >
> > --
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> > Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:
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> >
>
>
>
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Checked by AVG Free Edition. 
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