Discussion about the Korg PolySix synthesizer

What happens when I power on my Polysix is this: All led's lit up 
steady except för the freq. led on the MW section. It starts
blinking 
slowly and speeds up until it's a steady light. Another exception is 
the speed led on the arpeggiator section it blinks correct according 
to the speed set on the nob. I guess the the synth i s stuck in the 
reset mode witch should last a couple of seconds but I've waited for 
houers. Of cource there is no sound what so ever. If I remember 
correctly it started with a waiting time of a couple of minutes and 
gradualy got worse over time. I have tryed the repare of a leaking 
battery, and whas optemistic since there where at leased one trace 
damaged. After first repair it still would'nt work so i ended up 
replacing all traces around IC31 .... but no luck!

So I'm hoping that anyone out there has a clue how to fix it. Maybe 
there is some components at the reset circutes that has to changed.

Thanks 

Christer

hi,

i had the same problems on my two Polysix.Changed the 74LS08, changed 
the DAC-Chip, changed nearly everything. Nothing worked. The Knob 
Mainboard with the 4051\ufffds are ok.. As the result i think that the 8048 
is/was defect.

The Arp knob works with a own Clock source (a NE555 clock source is 
located on the board which holds the knob and the other arp-switches).

At the end i gave it up, it was not worth to fix them. I study currently 
how the other Boards work and i have also putted a C64 into one Polysix 
and currently program a Synthesizer-Control program, first in BASIC to 
see if all works corretly, then in Assembler.. Why not? The Keyboard 
Connector fits really great into the C64\ufffds Keyboard Connector (instead 
of read out the C64-Keyboard i read out pressed keys) , you have to use 
three/four lines of the User-Port for Controlling the 4051\ufffds on the Knob 
Board, you have two Paddle-Inputs to read out the Knob-Data and the rest 
will be done with some external Chips. You have enough place for the 
Voltage converter, you have Tape in-out on the back side of the 
Polysix-Case for connecting directly to the C64, you have through the 
Arpeggiator a excellent 1-line Clock source, you can have also 
additonally a Video-out-signal to make show additionally a little 
Sequencer andandand....the very basic Synth works already, of course in 
a horrible response time (BASIC is slow, unfortunaly), but i work on it.....

  So i do my own Version of a C64-Syntehsizer. I call it "Polythree" ;)

Greetings

stef.


cjansson2003 wrote:

>What happens when I power on my Polysix is this: All led's lit up 
>steady except f\ufffdr the freq. led on the MW section. It starts
>blinking 
>slowly and speeds up until it's a steady light. Another exception is 
>the speed led on the arpeggiator section it blinks correct according 
>to the speed set on the nob. I guess the the synth i s stuck in the 
>reset mode witch should last a couple of seconds but I've waited for 
>houers. Of cource there is no sound what so ever. If I remember 
>correctly it started with a waiting time of a couple of minutes and 
>gradualy got worse over time. I have tryed the repare of a leaking 
>battery, and whas optemistic since there where at leased one trace 
>damaged. After first repair it still would'nt work so i ended up 
>replacing all traces around IC31 .... but no luck!
>
>So I'm hoping that anyone out there has a clue how to fix it. Maybe 
>there is some components at the reset circutes that has to changed.
>
>Thanks 
>
>Christer
>
>
>
>
>To unsubscribe from this group, send an email to:
>PolySix-unsubscribe@egroups.com
>
>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6 
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
>
>
>
>  
>

That is one of the craziest pieces of hacking I have *ever* heard
about :-)

My polysix seems to have probs with its RESET mode too -
it used to get stuck in reset for several minutes,
and now is not liking the MIDI retrofit we're trying to
install...

If anyone has any more info on RESET problems, please let me
know...


----- Original Message ----- 
From: "Stefan Rinass" <st@rinass.de>
To: <PolySix@yahoogroups.com>
Sent: Friday, August 08, 2003 9:44 PM
Subject: Re: [PolySix] All led's lit up an then nothing moore
happens!!


> hi,
>
> i had the same problems on my two Polysix.Changed the 74LS08,
changed
> the DAC-Chip, changed nearly everything. Nothing worked. The
Knob
> Mainboard with the 4051\ufffds are ok.. As the result i think that
the 8048
> is/was defect.
>
> The Arp knob works with a own Clock source (a NE555 clock
source is
> located on the board which holds the knob and the other
arp-switches).
>
> At the end i gave it up, it was not worth to fix them. I study
currently
> how the other Boards work and i have also putted a C64 into one
Polysix
> and currently program a Synthesizer-Control program, first in
BASIC to
> see if all works corretly, then in Assembler.. Why not? The
Keyboard
> Connector fits really great into the C64\ufffds Keyboard Connector
(instead
> of read out the C64-Keyboard i read out pressed keys) , you
have to use
> three/four lines of the User-Port for Controlling the 4051\ufffds on
the Knob
> Board, you have two Paddle-Inputs to read out the Knob-Data and
the rest
> will be done with some external Chips. You have enough place
for the
> Voltage converter, you have Tape in-out on the back side of the
> Polysix-Case for connecting directly to the C64, you have
through the
> Arpeggiator a excellent 1-line Clock source, you can have also
> additonally a Video-out-signal to make show additionally a
little
> Sequencer andandand....the very basic Synth works already, of
course in
> a horrible response time (BASIC is slow, unfortunaly), but i
work on it.....
>
>   So i do my own Version of a C64-Syntehsizer. I call it
"Polythree" ;)
>
> Greetings
>
> stef.
>
>
> cjansson2003 wrote:
>
> >What happens when I power on my Polysix is this: All led's lit
up
> >steady except f\ufffdr the freq. led on the MW section. It starts
> >blinking
> >slowly and speeds up until it's a steady light. Another
exception is
> >the speed led on the arpeggiator section it blinks correct
according
> >to the speed set on the nob. I guess the the synth i s stuck
in the
> >reset mode witch should last a couple of seconds but I've
waited for
> >houers. Of cource there is no sound what so ever. If I
remember
> >correctly it started with a waiting time of a couple of
minutes and
> >gradualy got worse over time. I have tryed the repare of a
leaking
> >battery, and whas optemistic since there where at leased one
trace
> >damaged. After first repair it still would'nt work so i ended
up
> >replacing all traces around IC31 .... but no luck!
> >
> >So I'm hoping that anyone out there has a clue how to fix it.
Maybe
> >there is some components at the reset circutes that has to
changed.
> >
> >Thanks
> >
> >Christer
> >
> >
> >
> >
> >To unsubscribe from this group, send an email to:
> >PolySix-unsubscribe@egroups.com
> >
> >PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> >Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
> >
> >
>
>
>
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>
>

Hi there,

First thing I would do is check the Reset circuit according to the
service manual. The reset pulse can be adjusted. The service manual
along with the adjustment procedure is available at the web site of
"Old Crow":
http://www.oldcrows.net/~oldcrow/synth/korg/polysix/manuals/service/miniserv.html
The reset input to IC22 is pin4. It must be high (ca. +5V). If it is
below 3V the reset circuitry (around IC5) is faulty.

The next thing you can check is whether the 8048 is running:
monitor test point "CLOCK" left of the 8048 with an oscilloscope.
There must be a short pulse every 20msec.

The third thing is to check whether the crystal oscillator is running.
monitor pin 3 of IC22 (8048). This is the crystal osc. output. There
must be an oscillating waveform with about 6MHz. If you do not have
an oscilloscope you can monitor this pin with a DVM; it should read
about the half supply voltage which will be 2.5V in this case. If the
crystal is not running you can unsolder the resonator X1 and obtain
the 6MHz from KLM-366: route a wire from KLM-366/IC4/pin3 (Key Assigner
CPU) to KLM-367/IC22/pin2.

If you feel very confident that your 8048 chip is blown you may contact
me, I have a lot of them on stock. I think "Old Crow" has some of them,
too. But my eperience is that very seldom the CPU chip is defect. Much
more likely some of the circuitry around is the cause.

If you are really desperate about your Polysix you may contact me.
You can send me your KLM-367 board and I repair it for you. We have
to agree about the conditions.

I hope this helps,

Johannes

Have a look at (you will find my private email address there):
    http://analog.no/polysix/index.htm



PolySix@yahoogroups.com wrote:
  > What happens when I power on my Polysix is this: All led's lit up
  > steady except f\ufffdr the freq. led on the MW section. It starts
  > blinking
  > slowly and speeds up until it's a steady light. Another exception is
  > the speed led on the arpeggiator section it blinks correct according
  > to the speed set on the nob. I guess the the synth i s stuck in the
  > reset mode witch should last a couple of seconds but I've waited for
  > houers. Of cource there is no sound what so ever. If I remember
  > correctly it started with a waiting time of a couple of minutes and
  > gradualy got worse over time. I have tryed the repare of a leaking
  > battery, and whas optemistic since there where at leased one trace
  > damaged. After first repair it still would'nt work so i ended up
  > replacing all traces around IC31 .... but no luck!
  >
  > So I'm hoping that anyone out there has a clue how to fix it. Maybe
  > there is some components at the reset circutes that has to changed.
  >
  > Thanks
  >
  > Christer
  >
  >
  >
  >
  > To unsubscribe from this group, send an email to:
  > PolySix-unsubscribe@egroups.com
  >
  > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
  >
  > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/

  >
  >
  >
  >
  > .
  >