Discussion about the Korg PolySix synthesizer

Guys,

I have an issue showing up on my KLM-371 board. Bank B and Program 2 LEDs are on all the time. The system still lets me toggle through the 32 patch memories, but for example, if D8 is selected, four LED's are on : B,D,2,8.
What would cause the B and 2 LED's to stay on even after restarting?

Thanks

John

Two more symptoms to add to the LED thing, as I went through every knob and switch: My suboscillator no longer works and my 16' octave setting is the same as the 4' , so now it sounds really thin... ..... any ideas are welcome, it's my baby :-(

I just got a PolySix in trade with the same symptoms.
(same LEDs stuck on, 16' = 4' and no sub-osc).

I have no resolution yet - but I'm working on it.

--- In PolySix@yahoogroups.com, "Jw W" <arpomni@...> wrote:
>
> Two more symptoms to add to the LED thing, as I went through every knob and switch: My suboscillator no longer works and my 16' octave setting is the same as the 4' , so now it sounds really thin... ..... any ideas are welcome, it's my baby :-(
>

LFO led fix



http://audio.synth.vintage.free.fr/modules.php?name=Forums&file=viewtopic&t=
65&sid=c48f0ff6a4c55b7066f735b6f3725a91



De : PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] De la part de
John
Envoyé : jeudi 20 septembre 2012 00:58
À : PolySix@yahoogroups.com
Objet : [PolySix] Re: LEDs Stuck on





I just got a PolySix in trade with the same symptoms.
(same LEDs stuck on, 16' = 4' and no sub-osc).

I have no resolution yet - but I'm working on it.

--- In <mailto:PolySix%40yahoogroups.com> PolySix@yahoogroups.com, "Jw W" <
<mailto:arpomni@...> arpomni@...> wrote:

>
> Two more symptoms to add to the LED thing, as I went through every knob

and switch: My suboscillator no longer works and my 16' octave setting is
the same as the 4' , so now it sounds really thin... ..... any ideas are
welcome, it's my baby :-(

>

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

Hi,

Some of you would probably have done this before, but I was messing around
with my Polysix some days ago, after I got a Prophet 5. Naturally, the
Prophet 5's synth brass was really FAT, so I went about to see how much
the Poly6 could "stack up" against it!

Of course, the Poly6 was nowhere near as fat a brass sound compared to the
Prophet 5, but after I created this brassy patch on my Poly6 and "lost
interest" in it(!!), I hit the "Unison" mode while having the Arpeggio on,
set to 1Octave, Up&Down and lo and behold, I got this SIX oscillator FAT
synth BASS (out from that brass patch I created)!! :D

Now, this was something even the Prophet couldn't do, due to its lack of
Arpeggio!
I also happen to have this sync box (from eBay) that could take a MIDI
input and convert it to arpeggio triggers of various note values that the
Poly6 could sync to, and suddenly, I have this very cool big and fat, 6
oscillator, unison bass thumping along to eighth notes with my sequenced
parts (I was using Sonar X1) :DD
Nice!! :)

Khew

Thanks, but your LFO LED link is a dead one, and the problem we have is on the programming display LED's

Question to the smart guys on here: Why is the subosc and the octave switch messed, as well as the programming section? I'm thinking CPU or Memory Chip 32?

I pulled the board out. Power supply output is perfect. Replaced IC 30 and 31. Replaced the 40 pin socket for the CPU. Checked all of my traces for continuity as per Old Crow's site. I replaced the battery a couple years back and had a little corrosion, so the traces are fine on my board. I put it all back together and now have LED #5 stuck on now along with Found/Manual LED is also stuck on. My next step will be to replace IC32 with one on order, not easy to find that old memory chip! Hopefully this will be the fix. If not I will be ordering a new CPU chip from ?? Vintage Planet?? I guess. Any one have any other ideas or advice? I cannot believe how sad a broken Polysix makes me. It is a sweet machine.

John

If you had some visible corrosion it is very possible that there is/was
more hidden elsewhere that you missed. Or that got worse over time. That
stuff is insidious.

I would suggest doing a lot of continuity checking to rule that or a short
out as the culprit. Perhaps some other folks can chime in on where to
start.

jed

On Thu, Sep 20, 2012 at 7:59 AM, Jw W <arpomni@yahoo.com> wrote:

> **
>
>
> Thanks, but your LFO LED link is a dead one, and the problem we have is on
> the programming display LED's
>
> Question to the smart guys on here: Why is the subosc and the octave
> switch messed, as well as the programming section? I'm thinking CPU or
> Memory Chip 32?
>
> I pulled the board out. Power supply output is perfect. Replaced IC 30 and
> 31. Replaced the 40 pin socket for the CPU. Checked all of my traces for
> continuity as per Old Crow's site. I replaced the battery a couple years
> back and had a little corrosion, so the traces are fine on my board. I put
> it all back together and now have LED #5 stuck on now along with
> Found/Manual LED is also stuck on. My next step will be to replace IC32
> with one on order, not easy to find that old memory chip! Hopefully this
> will be the fix. If not I will be ordering a new CPU chip from ?? Vintage
> Planet?? I guess. Any one have any other ideas or advice? I cannot believe
> how sad a broken Polysix makes me. It is a sweet machine.
>
> John
>
>
>


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

As far as I know the memory chip will not result in such a behaviour. In
fact, the CPU board will work fine without the memory chip (of course
without the ability to store sounds).

Continuity is a good thing but it doesn't reveal if there are additional
shorts between traces.

Both the VCO octave switch and the sub octave switch use the same lines:
P10 and P11.
You might want to check the following functions:

EG Switch
Effects switch
Attenuator

I'm quite certain that either the P10 or P11 connection is broken somewhere
(or possibly both, I will have to check the PCB layout for this.)

More thoughts.

Both the "B" and "2" LEDs are served by D01.

D01 is also used by the Subosc switch (and the Mod switch); however the
Octave switch (and the Waveform switch) use D00 (if the documentation is
correct; I haven't checked this with the PCB yet).

D01 comes from pin 6 of IC31. It should also connect to the R17 array.

IC31 also should connect from pin 12 to the processor pin 13.

Seeing that IC31 and its traces are usually most affected by the battery
problem I'd look for the problem there first.

Guys,

Good news. No more LED's stuck on. You totally helped me out. Jed was right. I found 2 traces that needed a jumper. So much for my 'continuity is all good' comment. Odd how I replaced the battery 2 years ago and it was working great until last week. This corrosion thing is a bitch. Turns out the the issue was related to IC 30 pin2 and Pin 3 needing jumpers. Now the whole keyboard seems to work as it should EXCEPT for this one thing:

I can't seem to get the tape to work. I ran the test mode for A/D and cannot get LED's 1 and 8 to come on. Only 1 and 5 do, and the VR6 and VR7 adjustment only moves 1 up and down. Thoughts?

John

That *is* good news - I'll check those traces on my P6 tonight.

--- In PolySix@yahoogroups.com, "Jw W" <arpomni@...> wrote:

> Good news. No more LED's stuck on. You totally helped me out. Jed was right. I found 2 traces that needed a jumper. So much for my 'continuity is all good' comment. Odd how I replaced the battery 2 years ago and it was working great until last week. This corrosion thing is a bitch.