Discussion about the Korg PolySix synthesizer

I have a nice looking P6 here. Battery has leaked and severely damaged
the 74L08 near it and all traces beneath. The symptoms where
non-functioning Release and VCO '16 Oct functions, and cases where a
few preset leds light up together including the Write button led which
will sometimes light on and will not turn off. Also, pitch and cutoff
can change spontaneously as you play some chords.

I had it retraced and cleaned of course, and replaced the 74LS08 and
4011 above the battery (although the latter looked ok).

The current situation is that the Release and VCO '16 Oct functions
work ok, but the mess with the bank preset leds still exists. Can you
spot a particular IC which can cause the problem ? Other ideas ?

-HELLO
THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) AND REPLACE THIS 
IC´S
AND THE VIAS OF THE BOARD CAN BE BAD.
SORRY FOR MY ENGLISH.....
MERRY CHRISTMAS!!
-- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> I have a nice looking P6 here. Battery has leaked and severely damaged
> the 74L08 near it and all traces beneath. The symptoms where
> non-functioning Release and VCO '16 Oct functions, and cases where a
> few preset leds light up together including the Write button led which
> will sometimes light on and will not turn off. Also, pitch and cutoff
> can change spontaneously as you play some chords.
> 
> I had it retraced and cleaned of course, and replaced the 74LS08 and
> 4011 above the battery (although the latter looked ok).
> 
> The current situation is that the Release and VCO '16 Oct functions
> work ok, but the mess with the bank preset leds still exists. Can you
> spot a particular IC which can cause the problem ? Other ideas ?
>

Problem solved. IC30 has been replaced as well (leftmost on board).
BTW, before replacing it I noticed that the leds which where on,
were the Write and bank 6. If you check the schematics, you'll find
that they both connect through the same rail to IC31's leg number 6.
(pin 11 of connector CN10, "D06" rail on KLM367 schematics). Very
small degree of corrosion and acid was found under this IC as well.

Cheers !


--- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> I have a nice looking P6 here. Battery has leaked and severely damaged
> the 74L08 near it and all traces beneath. The symptoms where
> non-functioning Release and VCO '16 Oct functions, and cases where a
> few preset leds light up together including the Write button led which
> will sometimes light on and will not turn off. Also, pitch and cutoff
> can change spontaneously as you play some chords.
> 
> I had it retraced and cleaned of course, and replaced the 74LS08 and
> 4011 above the battery (although the latter looked ok).
> 
> The current situation is that the Release and VCO '16 Oct functions
> work ok, but the mess with the bank preset leds still exists. Can you
> spot a particular IC which can cause the problem ? Other ideas ?
>

Sure. As I said, IC30 was the culprit.


--- In PolySix@yahoogroups.com, "muffclone" <muffclone@...> wrote:
>
> -HELLO
> THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) AND 
REPLACE THIS 
> IC´S
> AND THE VIAS OF THE BOARD CAN BE BAD.
> SORRY FOR MY ENGLISH.....
> MERRY CHRISTMAS!!
> -- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > I have a nice looking P6 here. Battery has leaked and severely 
damaged
> > the 74L08 near it and all traces beneath. The symptoms where
> > non-functioning Release and VCO '16 Oct functions, and cases 
where a
> > few preset leds light up together including the Write button led 
which
> > will sometimes light on and will not turn off. Also, pitch and 
cutoff
> > can change spontaneously as you play some chords.
> > 
> > I had it retraced and cleaned of course, and replaced the 74LS08 
and
> > 4011 above the battery (although the latter looked ok).
> > 
> > The current situation is that the Release and VCO '16 Oct 
functions
> > work ok, but the mess with the bank preset leds still exists. Can 
you

> > spot a particular IC which can cause the problem ? Other ideas ?
> >
>

It looks a few problems still remain -

I just noticed that whatever setting you use, the Chorus effect is
always working (very interesting sounding when using the Phaser or
Ensemble, which play with the Chorus....). Also, when I use the Oct 2
setting (on Sub Osc), the root sound doesn't play.

Can you think of any direction ? I suspected IC34 and IC29, but no
harm to them and no corrosion at all at this area....

Thanks !



--- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> Sure. As I said, IC30 was the culprit.
> 
> 
> --- In PolySix@yahoogroups.com, "muffclone" <muffclone@> wrote:
> >
> > -HELLO
> > THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) AND 
> REPLACE THIS 
> > IC´S
> > AND THE VIAS OF THE BOARD CAN BE BAD.
> > SORRY FOR MY ENGLISH.....
> > MERRY CHRISTMAS!!
> > -- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > >
> > > I have a nice looking P6 here. Battery has leaked and severely 
> damaged
> > > the 74L08 near it and all traces beneath. The symptoms where
> > > non-functioning Release and VCO '16 Oct functions, and cases 
> where a
> > > few preset leds light up together including the Write button led 
> which
> > > will sometimes light on and will not turn off. Also, pitch and 
> cutoff
> > > can change spontaneously as you play some chords.
> > > 
> > > I had it retraced and cleaned of course, and replaced the 74LS08 
> and
> > > 4011 above the battery (although the latter looked ok).
> > > 
> > > The current situation is that the Release and VCO '16 Oct 
> functions
> > > work ok, but the mess with the bank preset leds still exists. Can 
> you
> > > spot a particular IC which can cause the problem ? Other ideas ?
> > >
> >
>

Urrrrrgggggg !

This is driving me nutz !

The chorus/Sub problem probably was related with bad contact of the 
panel connectors. This is OK now, but when I checked the instrument 
again, if worked well for a few minute, and just than started to make 
some noise as tweaking the knobs, and the programs section now 
sometimes doesn't let you get banks B, 2 and 6, and will lite up the 
Manual button led when pushing the "Write" button.

I can see on the schematics that the Write, B, 2 and 6 buttons are 
all connected to IC30 eventually, but it was already replaced, and 
has no bad traces going from it.










--- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> It looks a few problems still remain -
> 
> I just noticed that whatever setting you use, the Chorus effect is
> always working (very interesting sounding when using the Phaser or
> Ensemble, which play with the Chorus....). Also, when I use the Oct 
2
> setting (on Sub Osc), the root sound doesn't play.
> 
> Can you think of any direction ? I suspected IC34 and IC29, but no
> harm to them and no corrosion at all at this area....
> 
> Thanks !
> 
> 
> 
> --- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Sure. As I said, IC30 was the culprit.
> > 
> > 
> > --- In PolySix@yahoogroups.com, "muffclone" <muffclone@> wrote:
> > >
> > > -HELLO
> > > THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) 
AND 
> > REPLACE THIS 
> > > IC´S
> > > AND THE VIAS OF THE BOARD CAN BE BAD.
> > > SORRY FOR MY ENGLISH.....
> > > MERRY CHRISTMAS!!
> > > -- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > > >
> > > > I have a nice looking P6 here. Battery has leaked and 
severely 
> > damaged
> > > > the 74L08 near it and all traces beneath. The symptoms where
> > > > non-functioning Release and VCO '16 Oct functions, and cases 
> > where a
> > > > few preset leds light up together including the Write button 
led 
> > which
> > > > will sometimes light on and will not turn off. Also, pitch 
and 
> > cutoff
> > > > can change spontaneously as you play some chords.
> > > > 
> > > > I had it retraced and cleaned of course, and replaced the 
74LS08 
> > and
> > > > 4011 above the battery (although the latter looked ok).
> > > > 
> > > > The current situation is that the Release and VCO '16 Oct 
> > functions
> > > > work ok, but the mess with the bank preset leds still exists. 
Can 
> > you
> > > > spot a particular IC which can cause the problem ? Other 
ideas ?

> > > >
> > >
> >
>

yes, very frustrating...
My polysix has similarly #6, D and write on all the time and it has new IC 30 and 31...I cant figure where the continuity happens      unless, as i have heard , The pc board itself has conductivity  from the battery leakage..?  I found that scraping the traces away didnt solve the constantly on LED problems.  There seems to just be ' stray continuity '  so these switches are always on.  I havent solved this problem yet. I wish i had info on what each pin of IC 30 and 31 did. and which connected to which  letter/number LED's.

----- Original Message ----
From: gil_we <gil_we@yahoo.com>
To: PolySix@yahoogroups.com
Sent: Wednesday, December 26, 2007 7:28:06 PM
Subject: [PolySix] Re: now Chorus always on, Sub 2 Oct doesn't play root....

Urrrrrgggggg !

This is driving me nutz !

The chorus/Sub problem probably was related with bad contact of the 
panel connectors. This is OK now, but when I checked the instrument 
again, if worked well for a few minute, and just than started to make 
some noise as tweaking the knobs, and the programs section now 
sometimes doesn't let you get banks B, 2 and 6, and will lite up the 
Manual button led when pushing the "Write" button.

I can see on the schematics that the Write, B, 2 and 6 buttons are 
all connected to IC30 eventually, but it was already replaced, and 
has no bad traces going from it.

--- In PolySix@yahoogroups .com, "gil_we" <gil_we@...> wrote:
>
> It looks a few problems still remain -
> 
> I just noticed that whatever setting you use, the Chorus effect is
> always working (very interesting sounding when using the Phaser or
> Ensemble, which play with the Chorus.....). Also, when I use the Oct 
2
> setting (on Sub Osc), the root sound doesn't play.
> 
> Can you think of any direction ? I suspected IC34 and IC29, but no
> harm to them and no corrosion at all at this area....
> 
> Thanks !
> 
> 
> 
> --- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> >
> > Sure. As I said, IC30 was the culprit.
> > 
> > 
> > --- In PolySix@yahoogroups .com, "muffclone" <muffclone@> wrote:
> > >
> > > -HELLO
> > > THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) 
AND 
> > REPLACE THIS 
> > > IC´S
> > > AND THE VIAS OF THE BOARD CAN BE BAD.
> > > SORRY FOR MY ENGLISH.....
> > > MERRY CHRISTMAS!!
> > > -- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> > > >
> > > > I have a nice looking P6 here. Battery has leaked and 
severely 
> > damaged
> > > > the 74L08 near it and all traces beneath. The symptoms where
> > > > non-functioning Release and VCO '16 Oct functions, and cases 
> > where a
> > > > few preset leds light up together including the Write button 
led 
> > which
> > > > will sometimes light on and will not turn off. Also, pitch 
and 
> > cutoff
> > > > can change spontaneously as you play some chords.
> > > > 
> > > > I had it retraced and cleaned of course, and replaced the 
74LS08 
> > and
> > > > 4011 above the battery (although the latter looked ok).
> > > > 
> > > > The current situation is that the Release and VCO '16 Oct 
> > functions
> > > > work ok, but the mess with the bank preset leds still exists. 
Can 
> > you
> > > > spot a particular IC which can cause the problem ? Other 
ideas ?
> > > >
> > >
> >
>





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[Non-text portions of this message have been removed]

i had similar problems (i think #4 and D always on), but it still
worked okay for a year or so. then another problem appeared - the SUB
begun getting stuck and some problems with effects as well AFAIK. it
was really frustrating. at that point (after 4 or 5 repairs, i can't
remember) i have replaced both IC30, IC31, as well the main CPU (the
big 40-pin one near the resistor array) and repaired quite a lot of
traces. haven't scrapped them completely off though.

so else could i have done? i opened her up, took the board out, and
slowly started removing ALL the traces that looked even remotely
damaged. that means at some point, i had every single trace touching
IC30 and IC31 removed. quite a painful view. i also replaced the
resistor array. ALL the vias. i did just like in old crow's howto -
take an exacto and dig into the pcb, then try to get the trace to peel
off.

then i rewired it all, replaced the two ICs again, and - it works flawlessly.

jure

On Dec 27, 2007 5:17 AM, steven pistrich <wasteking1@yahoo.com> wrote:
> yes, very frustrating...
> My polysix has similarly #6, D and write on all the time and it has new IC 30 and 31...I cant figure where the continuity happens      unless, as i have heard , The pc board itself has conductivity  from the battery leakage..?  I found that scraping the traces away didnt solve the constantly on LED problems.  There seems to just be ' stray continuity '  so these switches are always on.  I havent solved this problem yet. I wish i had info on what each pin of IC 30 and 31 did. and which connected to which  letter/number LED's.
>
>
>
> ----- Original Message ----
> From: gil_we <gil_we@yahoo.com>
> To: PolySix@yahoogroups.com
> Sent: Wednesday, December 26, 2007 7:28:06 PM
> Subject: [PolySix] Re: now Chorus always on, Sub 2 Oct doesn't play root....
>
> Urrrrrgggggg !
>
> This is driving me nutz !
>
> The chorus/Sub problem probably was related with bad contact of the
> panel connectors. This is OK now, but when I checked the instrument
> again, if worked well for a few minute, and just than started to make
> some noise as tweaking the knobs, and the programs section now
> sometimes doesn't let you get banks B, 2 and 6, and will lite up the
> Manual button led when pushing the "Write" button.
>
> I can see on the schematics that the Write, B, 2 and 6 buttons are
> all connected to IC30 eventually, but it was already replaced, and
> has no bad traces going from it.
>
> --- In PolySix@yahoogroups .com, "gil_we" <gil_we@...> wrote:
> >
> > It looks a few problems still remain -
> >
> > I just noticed that whatever setting you use, the Chorus effect is
> > always working (very interesting sounding when using the Phaser or
> > Ensemble, which play with the Chorus.....). Also, when I use the Oct
> 2
> > setting (on Sub Osc), the root sound doesn't play.
> >
> > Can you think of any direction ? I suspected IC34 and IC29, but no
> > harm to them and no corrosion at all at this area....
> >
> > Thanks !
> >
> >
> >
> > --- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> > >
> > > Sure. As I said, IC30 was the culprit.
> > >
> > >
> > > --- In PolySix@yahoogroups .com, "muffclone" <muffclone@> wrote:
> > > >
> > > > -HELLO
> > > > THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08)
> AND
> > > REPLACE THIS
> > > > IC´S
> > > > AND THE VIAS OF THE BOARD CAN BE BAD.
> > > > SORRY FOR MY ENGLISH.....
> > > > MERRY CHRISTMAS!!
> > > > -- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> > > > >
> > > > > I have a nice looking P6 here. Battery has leaked and
> severely
> > > damaged
> > > > > the 74L08 near it and all traces beneath. The symptoms where
> > > > > non-functioning Release and VCO '16 Oct functions, and cases
> > > where a
> > > > > few preset leds light up together including the Write button
> led
> > > which
> > > > > will sometimes light on and will not turn off. Also, pitch
> and
> > > cutoff
> > > > > can change spontaneously as you play some chords.
> > > > >
> > > > > I had it retraced and cleaned of course, and replaced the
> 74LS08
> > > and
> > > > > 4011 above the battery (although the latter looked ok).
> > > > >
> > > > > The current situation is that the Release and VCO '16 Oct
> > > functions
> > > > > work ok, but the mess with the bank preset leds still exists.
> Can
> > > you
> > > > > spot a particular IC which can cause the problem ? Other
> ideas ?
> > > > >
> > > >
> > >
> >
>
>
>
>
>
>       ____________________________________________________________________________________
> Looking for last minute shopping deals?
> Find them fast with Yahoo! Search.  http://tools.search.yahoo.com/newsearch/category.php?category=shopping
>
> [Non-text portions of this message have been removed]
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>

You can see that on the schematics.


--- In PolySix@yahoogroups.com, steven pistrich <wasteking1@...> wrote:
>
> yes, very frustrating...
> My polysix has similarly #6, D and write on all the time and it has
new IC 30 and 31...I cant figure where the continuity happens     
unless, as i have heard , The pc board itself has conductivity  from
the battery leakage..?  I found that scraping the traces away didnt
solve the constantly on LED problems.  There seems to just be ' stray
continuity '  so these switches are always on.  I havent solved this
problem yet. I wish i had info on what each pin of IC 30 and 31 did.
and which connected to which  letter/number LED's.
> 
> 
> ----- Original Message ----
> From: gil_we <gil_we@...>
> To: PolySix@yahoogroups.com
> Sent: Wednesday, December 26, 2007 7:28:06 PM
> Subject: [PolySix] Re: now Chorus always on, Sub 2 Oct doesn't play
root....
> 
> Urrrrrgggggg !
> 
> This is driving me nutz !
> 
> The chorus/Sub problem probably was related with bad contact of the 
> panel connectors. This is OK now, but when I checked the instrument 
> again, if worked well for a few minute, and just than started to make 
> some noise as tweaking the knobs, and the programs section now 
> sometimes doesn't let you get banks B, 2 and 6, and will lite up the 
> Manual button led when pushing the "Write" button.
> 
> I can see on the schematics that the Write, B, 2 and 6 buttons are 
> all connected to IC30 eventually, but it was already replaced, and 
> has no bad traces going from it.
> 
> --- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> >
> > It looks a few problems still remain -
> > 
> > I just noticed that whatever setting you use, the Chorus effect is
> > always working (very interesting sounding when using the Phaser or
> > Ensemble, which play with the Chorus.....). Also, when I use the Oct 
> 2
> > setting (on Sub Osc), the root sound doesn't play.
> > 
> > Can you think of any direction ? I suspected IC34 and IC29, but no
> > harm to them and no corrosion at all at this area....
> > 
> > Thanks !
> > 
> > 
> > 
> > --- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> > >
> > > Sure. As I said, IC30 was the culprit.
> > > 
> > > 
> > > --- In PolySix@yahoogroups .com, "muffclone" <muffclone@> wrote:
> > > >
> > > > -HELLO
> > > > THIS PROBLEM IS THE BAD TRACES OF IC30 AND IC31 (TWO 74LS08) 
> AND 
> > > REPLACE THIS 
> > > > IC´S
> > > > AND THE VIAS OF THE BOARD CAN BE BAD.
> > > > SORRY FOR MY ENGLISH.....
> > > > MERRY CHRISTMAS!!
> > > > -- In PolySix@yahoogroups .com, "gil_we" <gil_we@> wrote:
> > > > >
> > > > > I have a nice looking P6 here. Battery has leaked and 
> severely 
> > > damaged
> > > > > the 74L08 near it and all traces beneath. The symptoms where
> > > > > non-functioning Release and VCO '16 Oct functions, and cases 
> > > where a
> > > > > few preset leds light up together including the Write button 
> led 
> > > which
> > > > > will sometimes light on and will not turn off. Also, pitch 
> and 
> > > cutoff
> > > > > can change spontaneously as you play some chords.
> > > > > 
> > > > > I had it retraced and cleaned of course, and replaced the 
> 74LS08 
> > > and
> > > > > 4011 above the battery (although the latter looked ok).
> > > > > 
> > > > > The current situation is that the Release and VCO '16 Oct 
> > > functions
> > > > > work ok, but the mess with the bank preset leds still exists. 
> Can 
> > > you
> > > > > spot a particular IC which can cause the problem ? Other 
> ideas ?
> > > > >
> > > >
> > >
> >
> 
> 
> 
> 
> 
>      
____________________________________________________________________________________
> Looking for last minute shopping deals?  
> Find them fast with Yahoo! Search. 
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> 
> [Non-text portions of this message have been removed]
>