Discussion about the Korg PolySix synthesizer

Sounds like D00 is shorted;  start by cutting the traces to that line 
around IC31 -- if the short goes away, you know where to look.  If not, 
cut the D00 trace to each of the other ICs & connectors, one at a time, 
checking the status of the short as you go.

~G
choco wrote:
>
> Hi.
>
> I've checked tha traces and seemed to be ok, but accidentaly I found
> something that I didn't understand.
>
> The D00 (CN06-3) seems to be connected to the +3.6 pin of the battery
> (and to the new diode which replaced the resistor there), and also to
> the D15 anode (which is really close to that trace). I removed the new
> diode and soldered it to the battery old soldering point which was not
> used and goes through the other side of the board. I cut the trace
> which connected the battery to the old resistor just for checking, but
> the connection was still there.
>
> Does it make any sense to you? The tracks and the board seem to be in
> good condition and the battery didn't almost leak when I replaced it,
> but it sounds to me that the board could be conductive or something
> like that.
>
> I just wanted to ask you before cutting all the traces on the board...
>
> Maybe tomorrow I will try to remove all the D00 traces and make cable
> connections.
>
> Thank you!
>
> --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>, 
> klosmon <klosmon@...> wrote:
> >
> > Most likely cause is another bad trace.
> > Check all the traces to CN06 (D00 - D03; P10 - P13).
> > Also keep in mind that these signals each have to connect to several
> > points on the board (for example, D00 connects to IC31-6, IC26-4,
> > CN06-3, IC28-4, IC34-4, etc etc).
> >
> > ~G
> >
> > choco wrote:
> > >
> > > Hi!
> > >
> > > Finnaly I managed to repair it! It was just a track that I cut
> > > accedentally and was under a printed number on the board (it was
> > > almost impossible to see it)
> > >
> > > Now I've got another problem. The synth sounds ok, it stores the
> > > presets and so on, but it seems to be a problem with the modulation
> > > section that it doesn't had before I managed to change the battery.
> > >
> > > What happens is: when i switch the P6 on the LFO led starts flashing
> > > faster and faster and every change of the pots doesn't affect to it.
> > > Did you encounter this problem before? I've tried to do the Modulation
> > > adjustment but the VR changes doesn't seem to affect to the signal
> > > that is delivered to CN03-5. Well, I'm doing it with a digital
> > > voltimeter which stands to measure Hz, but maybe that's not a good
> way...
> > >
> > > any idea?
> > >
> > > Thank you in advance.
> > >
> > > --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> 
> <mailto:PolySix%40yahoogroups.com>,
> > > "choco" <ignaciojimenez@> wrote:
> > > >
> > > > Hi-
> > > >
> > > > Thank you for your fast and kind reply.
> > > >
> > > > I have visited your website several times when doing research for my
> > > > P6 and I had you in mind as an option if I couldn't work it out. My
> > > > synth comes from the states and I was bothered about sending it
> back,
> > > > but I've never thought before about sending just the board. It's a
> > > > great option.
> > > >
> > > > I'll check one more time that traces and maybe I will re-solder them
> > > > and the socket more accurately just for testing.
> > > >
> > > > Probably I will contact you in a week if I can't arrange to
> repair it.
> > > >
> > > > And maybe I'll think about getting a scope.
> > > >
> > > > Thank you!
> > > >
> > > > --- In PolySix@yahoogroups.com 
> <mailto:PolySix%40yahoogroups.com> <mailto:PolySix%40yahoogroups.com>,
> > > klosmon <klosmon@> wrote:
> > > > >
> > > > > Hello-
> > > > > Having repaired many of these, I would suggest that the most
> likely
> > > > > cause is damaged traces due to the battery leak.
> > > > > Even if the board looks good, the traces around IC31 (which you
> > > > > replaced) are VERY delicate, and carry data lines that, if
> damaged,
> > > > > effect all of the functions of the synth.
> > > > >
> > > > > If you have any experience with electronics, get hold of the
> > > schematic
> > > > > and use a continuity tester to test all traces from that IC;
> if you
> > > > > have a scope, that's even faster.
> > > > >
> > > > > If not, you can send me the CPU board & I can look it over for
> you.
> > > > >
> > > > > ~GMM
> > > > > analogsynthervice.com
> > > > >
> > > > >
> > > > > choco wrote:
> > > > > >
> > > > > > Hi!
> > > > > >
> > > > > > After digging within the messages I haven't found any similar
> > > > > > situation, so I decided to post.
> > > > > >
> > > > > > I bought a year ago and old polysix and it sounded fine to
> me (maybe
> > > > > > lower than expected, I use it with an old guitar tube amp
> and I have
> > > > > > to select the high output with master at 12 o'clock to get it at
> > > > > > almost the same level as the guitar is)
> > > > > >
> > > > > > A mounth ago I noticed that I had lost all my patches (although
> > > it was
> > > > > > sounding great and every pot worked fine). I did know about the
> > > > > > battery issues, but it hadn't worried me until that moment.
> I opened
> > > > > > the polysix and noticed that the battery mounting clamps
> were broken
> > > > > > and the batery was not feeding the klm367A anymore.
> > > > > >
> > > > > > Well, it had leaked a little bit, but the circuit was almost
> perfect
> > > > > > and there were no signs of corrosion elsewhere. I cleaned
> all the
> > > > > > board with alcohol and care, replaced the battery and the
> 74LS08N
> > > > > > which is next to it just for security and then I made a mistake.
> > > > > >
> > > > > > I broke a trace and shorted accidentaly 5V and ground.
> > > > > >
> > > > > > After testing and noticing what the matter was, I removed that
> > > mistake
> > > > > > and everything seemed to work fine (the leds and so on), but
> when I
> > > > > > pluged the P6 to an amp (to the earphones too), I noticed
> that it
> > > > > > sounded weak and something like distorted. almost every pot
> didn't
> > > > > > affect as expected.
> > > > > >
> > > > > > Do you have any idea of what can happen to my beloved P6?Any
> measure
> > > > > > that I could take from it to get deeper into? Unfortunately
> I don't
> > > > > > have an osciloscope to take accurate measures...
> > > > > >
> > > > > > I also had a problem with 15Volt line, all the LEDs were ON when
> > > > > > starting up the P6, but never went OFF. In addition to it, the
> > > > > > Modulation LFO LED started blinking every time faster and faster
> > > until
> > > > > > it seemed to be just static ON. I solved it regulating the 15V
> > > pot to
> > > > > > get over 15.05 on my meter.
> > > > > >
> > > > > > I will continue testing it, but it seems that I have reached
> my best
> > > > > > effort in front of it, and here in Spain it's almost impossible
> > > > > > finding a qualified vintage synth tech.
> > > > > >
> > > > > > Thank you in advance.
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > [Non-text portions of this message have been removed]
> > > > >
> > > >
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>  



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