Discussion about the Korg PolySix synthesizer

Hello,
I recently acquired a polysix in rough shape. I tested out the battery board and the new connections for the corroded tracks seem to be all good. I have not installed the new battery yet but tested it out.
The arp functions along with the rate knob, the keys function but need all contacts cleaned badly. The control knobs do not effect sound at all except for the Attack which only functions rarely. The connectors leading from the battery board to the controls are good. The Mod wheel functions properly along with the bend and tune. Is there an obvious area to look at regarding this issue? Thanks for any input.
Best,
Eric

I actually found and fixed two more bad traces buy checking and triple checking the board, my bad. Now the battery is installed and still the same problems exist. I can tell that pulse width modulation is happening and is stuck on. The Lfo LED appears to either be stuck on or going at a very high rate and none of the bank LEDs are lit. I believe all voices are functioning. Does anyone have any thoughts on this or is there by chance a prior post that would be good to read? I wasn't able to find anything obvious.
best,
Eric

--- In PolySix@yahoogroups.com, "eric.pitra" wrote:
>
> Hello,
> I recently acquired a polysix in rough shape. I tested out the battery board and the new connections for the corroded tracks seem to be all good. I have not installed the new battery yet but tested it out.
> The arp functions along with the rate knob, the keys function but need all contacts cleaned badly. The control knobs do not effect sound at all except for the Attack which only functions rarely. The connectors leading from the battery board to the controls are good. The Mod wheel functions properly along with the bend and tune. Is there an obvious area to look at regarding this issue? Thanks for any input.
> Best,
> Eric
>

Is there anyone in this group who could help me with this issue? I guess all I really need is to be pointed in the right direction. I would love it if someone could help me out.
Thanks,
Eric

--- In PolySix@yahoogroups.com, "eric.pitra" wrote:
>
>
> I actually found and fixed two more bad traces buy checking and triple checking the board, my bad. Now the battery is installed and still the same problems exist. I can tell that pulse width modulation is happening and is stuck on. The Lfo LED appears to either be stuck on or going at a very high rate and none of the bank LEDs are lit. I believe all voices are functioning. Does anyone have any thoughts on this or is there by chance a prior post that would be good to read? I wasn't able to find anything obvious.
> best,
> Eric
>
> --- In PolySix@yahoogroups.com, "eric.pitra" wrote:
> >
> > Hello,
> > I recently acquired a polysix in rough shape. I tested out the battery board and the new connections for the corroded tracks seem to be all good. I have not installed the new battery yet but tested it out.
> > The arp functions along with the rate knob, the keys function but need all contacts cleaned badly. The control knobs do not effect sound at all except for the Attack which only functions rarely. The connectors leading from the battery board to the controls are good. The Mod wheel functions properly along with the bend and tune. Is there an obvious area to look at regarding this issue? Thanks for any input.
> > Best,
> > Eric
> >
>

The control pots are demultiplexed on the CPU board by ICs 18 and 19 --
the schematic for the CPU board shows which CV (Cutoff, Attack, Effects
Speed, etc) is controlled by which pin. A scope is essential for
tracking down this type of problem. Look at pins 9, 10 and 11 of those
two chips to see if all timing signals are present; look at pin 6 of
each chip to see if the timing signals are there. Pin 3 of each chip
should show you the ADC signal, which should show meaningful response
when any of the front panel pots is turned.

It's also possible the problem is on the front panel; check out the ADC
signal to connector CN11-2.

~G

On 1/17/2013 11:29 AM, eric.pitra wrote:
>
> Is there anyone in this group who could help me with this issue? I
> guess all I really need is to be pointed in the right direction. I
> would love it if someone could help me out.
> Thanks,
> Eric
>
> --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>,
> "eric.pitra" wrote:
> >
> >
> > I actually found and fixed two more bad traces buy checking and
> triple checking the board, my bad. Now the battery is installed and
> still the same problems exist. I can tell that pulse width modulation
> is happening and is stuck on. The Lfo LED appears to either be stuck
> on or going at a very high rate and none of the bank LEDs are lit. I
> believe all voices are functioning. Does anyone have any thoughts on
> this or is there by chance a prior post that would be good to read? I
> wasn't able to find anything obvious.
> > best,
> > Eric
> >
> > --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>,
> "eric.pitra" wrote:
> > >
> > > Hello,
> > > I recently acquired a polysix in rough shape. I tested out the
> battery board and the new connections for the corroded tracks seem to
> be all good. I have not installed the new battery yet but tested it out.
> > > The arp functions along with the rate knob, the keys function but
> need all contacts cleaned badly. The control knobs do not effect sound
> at all except for the Attack which only functions rarely. The
> connectors leading from the battery board to the controls are good.
> The Mod wheel functions properly along with the bend and tune. Is
> there an obvious area to look at regarding this issue? Thanks for any
> input.
> > > Best,
> > > Eric
> > >
> >
>
>



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

You say the connectors are good...did you check the continuity of the wires
or did you just look? The corrosion on my board went through the wires and
was not obvious.

From what you've written it sounds like you acquired a P6 where someone
else had already done some work on a damaged 367 board. They may not have
fixed all the underlying problems. The corrosion can damage the components
in addition to the traces. Start checking where indicated by the last
message.

On Thu, Jan 17, 2013 at 11:29 AM, eric.pitra <eric.pitra@gmail.com> wrote:

> **
>
>
> Is there anyone in this group who could help me with this issue? I guess
> all I really need is to be pointed in the right direction. I would love it
> if someone could help me out.
> Thanks,
> Eric
>
> --- In PolySix@yahoogroups.com, "eric.pitra" wrote:
> >
> >
> > I actually found and fixed two more bad traces buy checking and triple
> checking the board, my bad. Now the battery is installed and still the same
> problems exist. I can tell that pulse width modulation is happening and is
> stuck on. The Lfo LED appears to either be stuck on or going at a very high
> rate and none of the bank LEDs are lit. I believe all voices are
> functioning. Does anyone have any thoughts on this or is there by chance a
> prior post that would be good to read? I wasn't able to find anything
> obvious.
> > best,
> > Eric
> >
> > --- In PolySix@yahoogroups.com, "eric.pitra" wrote:
> > >
> > > Hello,
> > > I recently acquired a polysix in rough shape. I tested out the battery
> board and the new connections for the corroded tracks seem to be all good.
> I have not installed the new battery yet but tested it out.
> > > The arp functions along with the rate knob, the keys function but need
> all contacts cleaned badly. The control knobs do not effect sound at all
> except for the Attack which only functions rarely. The connectors leading
> from the battery board to the controls are good. The Mod wheel functions
> properly along with the bend and tune. Is there an obvious area to look at
> regarding this issue? Thanks for any input.
> > > Best,
> > > Eric
> > >
> >
>
>
>


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