Discussion about the Korg PolySix synthesizer

I have tested the buttons with a multimeter and they all successfully connect when held down.  The buttons each light up correctly; the unison patches display the unison LED.  The arpeggio rate LED responds correctly.

Check IC1 and the area around it on the 366 - especially for corrosion.

If the LEDs turn on and off when you press the corresponding switch, then the
8049 key assigner MCU is reading the switches correctly. I think all of the logic
to implement those features is in the code of that MCU. Maybe try replacing that chip?
Maybe you can borrow a good on just to try.

Bob

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On Thu, 4/28/16, chrismitchrocks@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

Subject: [PolySix] Apreggio, Chord Mode, Unison, Poly button do not work. Help?
To: PolySix@yahoogroups.com
Date: Thursday, April 28, 2016, 7:05 PM




I have tested the buttons with a multimeter and
they all successfully connect when held down.  The buttons
each light up correctly; the unison patches display the
unison LED.  The arpeggio rate LED responds
correctly.
I also
checked the ribbon cable going from the arpeggio knob board
to the buttons board and each of these wires were connected
properly.
Any ideas
what to check?  I thought about replace the buttons, but
since they connect fine it seems like they should
work.

What is (are) the actual problem(s)?
What do you mean by "the unison patches display the unison LED"?

When the button LEDs react reasonable to the button presses then the
CPU reads the buttons correctly.

Johannes

On 2016-04-29, 01:05 chrismitchrocks@yahoo.com [PolySix] wrote:
>
>
> I have tested the buttons with a multimeter and they all successfully
> connect when held down. The buttons each light up correctly; the unison
> patches display the unison LED. The arpeggio rate LED responds correctly.
>
> I also checked the ribbon cable going from the arpeggio knob board to
> the buttons board and each of these wires were connected properly.
>
> Any ideas what to check? I thought about replace the buttons, but since
> they connect fine it seems like they should work.
>
>
>
> ------------------------------------------------------------------------
> Posted by: chrismitchrocks@yahoo.com
> ------------------------------------------------------------------------
>
>

The problem is that the Polysix will not change modes or turn on the arpeggiator.

By"Modes" I mean the Key Assign Modes: Chord Mode, Unison, Poly, Hold buttons.

The keyboard mode is not stored together with a patch, at least not with
the stock CPU board.
Recalling any patch will not change the keyboard mode.

Ah.  Well I installed the Kiwisix replacement as I believed my KLM-367A was broken due to the issue I described earlier, and I guess that stores keyboard mode in a patch.

Is this a question of recalling them as patches.

Do the buttons work normally ?

I suggest that if you want us to help troubleshoot, and you really think the
problem is not associated with the Kiwi Six, you should
uninstall the Kiwi Six mod, and put the Poly 6 back to the stock configuration
that we are familiar with. Then we can work through the problem logically.
Having the Kiwi Six installed really makes that a lot harder.

My two cents.

OK what would you recommend I do once I'm back at this point but the regular KLM-367A is in the board?

Do you have an oscilloscope?

It's important to keep the following in mind:

The stock Polysix has two processors. The processor on the KLM-367 handles
everything that has to do with patches and sound programming (and related
knobs). The processor on the KLM-366 handles the keyboard scanning, voice
assignment, keyboard modes and arpeggiator. Both processor work
independently.

The Kiwisix board substitutes both processors. That's why you have the
ribbon cable going from the Kiwisix board to the KLM-366 board.

All voice modes are generated directly in the original processor. The CV's
for the voices are multiplexed, the gates are sent independently. This
means that it is highly unlikely that the problem resides somewhere on the
KLM-366 itself; if the proper LED's light up all the correct data lines are
working.

My guess is that it's a Kiwisix problem and possibly maybe just a
configuration thing. Problem with the voice board: unlikely; at least from
your description.

I don't have an oscilloscope but if it's necessary I can get one, it's been on my list to buy one for a while.

There's continuity between CN12, IC1, and from IC1 to IC2.  However IC1 does sort of look like there's some corrosion or some damage on its pins.  The white text on it has faded off while all the others exist there so it definitely stands out.  I don't know if that could mean it's overheated, but it also gets the proper 5v to its power.

> The switches you refer to arrive at IC1 on the 366 from the 371...

The switches arrive directly at the processor at pin 27 to 34. IC1 drives
(mostly) the LEDs for the switches.

Check the rest of the pins on IC1?  What is the best way to do this?  I'm not really sure how to test inverters.

Check the pins on the IC1?  What's the best way to do this?  I'm not really sure what you're meaning.

Check continuity between Pin 21 of the processor socket and Pin14 of CN12
on KLM371. Actually you should have continuity between this pin and one
side of all the button switches (but not the slide switches).

I could not get continuity between Pin 21 and any of the other pins.  

Well, then you need to find out where you lose the continuity.

Check continuity between IC6 socket pin 21 and pin 11 of IC29 and IC39
(you'll probably have that continuity because otherwise the voice board
wouldn't work at all). Check continuity between any of those pins and pin
14 of CN12 on KLM366. Then check continuity of the connecting cable.

The signal from pin 21 of IC6 (the original processor) and hence also from
the signal coming the Kiwisix board is used for those switches; it is also
used for a lot of other things. Since the voice board in general seems to
work the signal itself must be present on the voiceboard but it doesn't
make it to KLM-371.

OK After more testing it looks like CN12 Pin 14 isn't making it to IC1 pin 5, which also isn't making it to the pin which connects with IC6 pin 21.

OK she works now!  It was just the one bad connection.  Now time to tune her up and have some fun!

Excellent ! Also could me you've a working 367...

You won't do any damage checking it, although you'll here modulation due to the bender mod.

Have fun !

I'm going to be busy the next few days but I'll try to switch it out monday and check!

OK I tried the old board again and it seemed to be worse than before haha so I wouldn't want to bother with it, I'll assume it's dead.