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Discussion about the Korg PolySix synthesizer

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fault location advice needed

fault location advice needed

2006-01-30 by jure zitnik

here's the thing:
i'm not repairing the polysix myself but i'm still pretty involved
since the man repairing it doesn't have that much experience with
analogue synths. and i have zero experience with actual physical work
on synths :/

so - the polysix:
the battery leaked but the traces were repaired. this guy probably did
it all correctly but i'm not 100% sure. let's say they're alright now.
we also replaced IC31 (the lower of the 2 identical 4xAND gates) but
the symptoms are still the same as they were before the repair:
- synth usually works okay for the first half hour or so. except the
patch storage.
- patch programmer: bank 3 and prog 3 are lit all the time. you can
select another bank and program but nothing can be saved.
- the attenuator 13 way switch doesn't work at all.
- after some time other controls stop responding (and stay like they
were set): waveform selector, VCA gate mode and effect selector.
- usually when this happens some program and bank leds (actually bank
1 and 2 and program 2) start dimly blinking like there's some short
circuit or something. this gives me doubts whether it's really CPU
(IC21) fault. if it were faulty it would probably just die or
something... right?

so - what would you guys check next? how possible do you think it is
that it's the CPU? what about the 18-pin SRAM IC? any other ICs that
usually fail?

i really appreciate your help so far!

thanks!
jure

Re: fault location advice needed

2006-01-30 by gil_we

It sounds like the KLM-267A is not fully functioning yet


--- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
>
> here's the thing:
> i'm not repairing the polysix myself but i'm still pretty involved
> since the man repairing it doesn't have that much experience with
> analogue synths. and i have zero experience with actual physical 
work
> on synths :/
> 
> so - the polysix:
> the battery leaked but the traces were repaired. this guy probably 
did
> it all correctly but i'm not 100% sure. let's say they're alright 
now.
> we also replaced IC31 (the lower of the 2 identical 4xAND gates) but
> the symptoms are still the same as they were before the repair:
> - synth usually works okay for the first half hour or so. except the
> patch storage.
> - patch programmer: bank 3 and prog 3 are lit all the time. you can
> select another bank and program but nothing can be saved.
> - the attenuator 13 way switch doesn't work at all.
> - after some time other controls stop responding (and stay like they
> were set): waveform selector, VCA gate mode and effect selector.
> - usually when this happens some program and bank leds (actually 
bank
Show quoted textHide quoted text
> 1 and 2 and program 2) start dimly blinking like there's some short
> circuit or something. this gives me doubts whether it's really CPU
> (IC21) fault. if it were faulty it would probably just die or
> something... right?
> 
> so - what would you guys check next? how possible do you think it is
> that it's the CPU? what about the 18-pin SRAM IC? any other ICs that
> usually fail?
> 
> i really appreciate your help so far!
> 
> thanks!
> jure
>

Re: [PolySix] Re: fault location advice needed

2006-01-30 by jure zitnik

you mean KLM-367?

i wonder what could cause that led flashing?

jure
Show quoted textHide quoted text
On 1/30/06, gil_we <gil_we@yahoo.com> wrote:
> It sounds like the KLM-267A is not fully functioning yet
>
>
> --- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
> >
> > here's the thing:
> > i'm not repairing the polysix myself but i'm still pretty involved
> > since the man repairing it doesn't have that much experience with
> > analogue synths. and i have zero experience with actual physical
> work
> > on synths :/
> >
> > so - the polysix:
> > the battery leaked but the traces were repaired. this guy probably
> did
> > it all correctly but i'm not 100% sure. let's say they're alright
> now.
> > we also replaced IC31 (the lower of the 2 identical 4xAND gates) but
> > the symptoms are still the same as they were before the repair:
> > - synth usually works okay for the first half hour or so. except the
> > patch storage.
> > - patch programmer: bank 3 and prog 3 are lit all the time. you can
> > select another bank and program but nothing can be saved.
> > - the attenuator 13 way switch doesn't work at all.
> > - after some time other controls stop responding (and stay like they
> > were set): waveform selector, VCA gate mode and effect selector.
> > - usually when this happens some program and bank leds (actually
> bank
> > 1 and 2 and program 2) start dimly blinking like there's some short
> > circuit or something. this gives me doubts whether it's really CPU
> > (IC21) fault. if it were faulty it would probably just die or
> > something... right?
> >
> > so - what would you guys check next? how possible do you think it is
> > that it's the CPU? what about the 18-pin SRAM IC? any other ICs that
> > usually fail?
> >
> > i really appreciate your help so far!
> >
> > thanks!
> > jure
> >
>
>
>
>
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>
>
>
>

Re: fault location advice needed

2006-01-30 by gil_we

Yah I ment 367...

It looks like it hasn't be 100% repaired...
Can you see corrosion on other boards as well ?


--- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
>
> you mean KLM-367?
> 
> i wonder what could cause that led flashing?
> 
> jure
> 
> On 1/30/06, gil_we <gil_we@y...> wrote:
> > It sounds like the KLM-267A is not fully functioning yet
> >
> >
> > --- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
> > >
> > > here's the thing:
> > > i'm not repairing the polysix myself but i'm still pretty 
involved
> > > since the man repairing it doesn't have that much experience 
with
> > > analogue synths. and i have zero experience with actual physical
> > work
> > > on synths :/
> > >
> > > so - the polysix:
> > > the battery leaked but the traces were repaired. this guy 
probably
> > did
> > > it all correctly but i'm not 100% sure. let's say they're 
alright
> > now.
> > > we also replaced IC31 (the lower of the 2 identical 4xAND 
gates) but
> > > the symptoms are still the same as they were before the repair:
> > > - synth usually works okay for the first half hour or so. 
except the
> > > patch storage.
> > > - patch programmer: bank 3 and prog 3 are lit all the time. you 
can
> > > select another bank and program but nothing can be saved.
> > > - the attenuator 13 way switch doesn't work at all.
> > > - after some time other controls stop responding (and stay like 
they
> > > were set): waveform selector, VCA gate mode and effect selector.
> > > - usually when this happens some program and bank leds (actually
> > bank
> > > 1 and 2 and program 2) start dimly blinking like there's some 
short
> > > circuit or something. this gives me doubts whether it's really 
CPU
> > > (IC21) fault. if it were faulty it would probably just die or
> > > something... right?
> > >
> > > so - what would you guys check next? how possible do you think 
it is
> > > that it's the CPU? what about the 18-pin SRAM IC? any other ICs 
that
Show quoted textHide quoted text
> > > usually fail?
> > >
> > > i really appreciate your help so far!
> > >
> > > thanks!
> > > jure
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
>

Re: [PolySix] Re: fault location advice needed

2006-01-30 by jure zitnik

no not on other boards. just the 367. but that one's also cleaned now
and all...
Show quoted textHide quoted text
On 1/30/06, gil_we <gil_we@yahoo.com> wrote:
> Yah I ment 367...
>
> It looks like it hasn't be 100% repaired...
> Can you see corrosion on other boards as well ?
>
>
> --- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
> >
> > you mean KLM-367?
> >
> > i wonder what could cause that led flashing?
> >
> > jure
> >
> > On 1/30/06, gil_we <gil_we@y...> wrote:
> > > It sounds like the KLM-267A is not fully functioning yet
> > >
> > >
> > > --- In PolySix@yahoogroups.com, jure zitnik <kokoon@g...> wrote:
> > > >
> > > > here's the thing:
> > > > i'm not repairing the polysix myself but i'm still pretty
> involved
> > > > since the man repairing it doesn't have that much experience
> with
> > > > analogue synths. and i have zero experience with actual physical
> > > work
> > > > on synths :/
> > > >
> > > > so - the polysix:
> > > > the battery leaked but the traces were repaired. this guy
> probably
> > > did
> > > > it all correctly but i'm not 100% sure. let's say they're
> alright
> > > now.
> > > > we also replaced IC31 (the lower of the 2 identical 4xAND
> gates) but
> > > > the symptoms are still the same as they were before the repair:
> > > > - synth usually works okay for the first half hour or so.
> except the
> > > > patch storage.
> > > > - patch programmer: bank 3 and prog 3 are lit all the time. you
> can
> > > > select another bank and program but nothing can be saved.
> > > > - the attenuator 13 way switch doesn't work at all.
> > > > - after some time other controls stop responding (and stay like
> they
> > > > were set): waveform selector, VCA gate mode and effect selector.
> > > > - usually when this happens some program and bank leds (actually
> > > bank
> > > > 1 and 2 and program 2) start dimly blinking like there's some
> short
> > > > circuit or something. this gives me doubts whether it's really
> CPU
> > > > (IC21) fault. if it were faulty it would probably just die or
> > > > something... right?
> > > >
> > > > so - what would you guys check next? how possible do you think
> it is
> > > > that it's the CPU? what about the 18-pin SRAM IC? any other ICs
> that
> > > > usually fail?
> > > >
> > > > i really appreciate your help so far!
> > > >
> > > > thanks!
> > > > jure
> > > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
>
>
>
>
>
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>
>
>
>

Re: fault location advice needed

2008-01-20 by Daniel Akzinor

This describes my problem exactly... Did you ever find a fix?

- Daniel

--- In PolySix@yahoogroups.com, jure zitnik <kokoon@...> wrote:
>
> here's the thing:
> i'm not repairing the polysix myself but i'm still pretty involved
> since the man repairing it doesn't have that much experience with
> analogue synths. and i have zero experience with actual physical 
work
> on synths :/
> 
> so - the polysix:
> the battery leaked but the traces were repaired. this guy probably 
did
> it all correctly but i'm not 100% sure. let's say they're alright 
now.
> we also replaced IC31 (the lower of the 2 identical 4xAND gates) but
> the symptoms are still the same as they were before the repair:
> - synth usually works okay for the first half hour or so. except the
> patch storage.
> - patch programmer: bank 3 and prog 3 are lit all the time. you can
> select another bank and program but nothing can be saved.
> - the attenuator 13 way switch doesn't work at all.
> - after some time other controls stop responding (and stay like they
> were set): waveform selector, VCA gate mode and effect selector.
> - usually when this happens some program and bank leds (actually 
bank
Show quoted textHide quoted text
> 1 and 2 and program 2) start dimly blinking like there's some short
> circuit or something. this gives me doubts whether it's really CPU
> (IC21) fault. if it were faulty it would probably just die or
> something... right?
> 
> so - what would you guys check next? how possible do you think it is
> that it's the CPU? what about the 18-pin SRAM IC? any other ICs that
> usually fail?
> 
> i really appreciate your help so far!
> 
> thanks!
> jure
>

Re: [PolySix] Re: fault location advice needed

2008-01-21 by jure zitnik

yes, i've fixed it eventually. i've posted this a few times already
but here goes again:

REMOVE all the traces that look even remotely damaged by the battery
leak. seriously. just jumping them won't do it, you have to REMOVE
them. i dug them out with an exacto, just like old crow says.

i also replaced the resistor array in that area.

make sure you assemble the programmer switch board so, that none of
the keys are too tightly pressed to the frontpanel, at one point i
found out that was causing my problem of some LEDs being lit all the
time (keys were actually pressed)

and, once more, REMOVE EVERY SINGLE TRACE that looks corroded.

good luck!

jure
Show quoted textHide quoted text
On Jan 20, 2008 10:23 PM, Daniel Akzinor <apophis93@yahoo.com> wrote:
> This describes my problem exactly... Did you ever find a fix?
>
> - Daniel
>
>
> --- In PolySix@yahoogroups.com, jure zitnik <kokoon@...> wrote:
> >
> > here's the thing:
> > i'm not repairing the polysix myself but i'm still pretty involved
> > since the man repairing it doesn't have that much experience with
> > analogue synths. and i have zero experience with actual physical
> work
> > on synths :/
> >
> > so - the polysix:
> > the battery leaked but the traces were repaired. this guy probably
> did
> > it all correctly but i'm not 100% sure. let's say they're alright
> now.
> > we also replaced IC31 (the lower of the 2 identical 4xAND gates) but
> > the symptoms are still the same as they were before the repair:
> > - synth usually works okay for the first half hour or so. except the
> > patch storage.
> > - patch programmer: bank 3 and prog 3 are lit all the time. you can
> > select another bank and program but nothing can be saved.
> > - the attenuator 13 way switch doesn't work at all.
> > - after some time other controls stop responding (and stay like they
> > were set): waveform selector, VCA gate mode and effect selector.
> > - usually when this happens some program and bank leds (actually
> bank
> > 1 and 2 and program 2) start dimly blinking like there's some short
> > circuit or something. this gives me doubts whether it's really CPU
> > (IC21) fault. if it were faulty it would probably just die or
> > something... right?
> >
> > so - what would you guys check next? how possible do you think it is
> > that it's the CPU? what about the 18-pin SRAM IC? any other ICs that
> > usually fail?
> >
> > i really appreciate your help so far!
> >
> > thanks!
> > jure
> >
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>
>

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