Korg Poly800/EX800 Users

hey chaps. i recently bought this poly-800 mk1 ( my 3rd!) and it arrived with a non working SEQ Speed slider, sliding it up and down makes no difference to the seq speed. is this a common problem and is it fixable?

thanks

hello polyfans. great group by the way :)

So I've had my poly800 apart and couldnt find any obvious flaws regarding the non-working speed fader, I can input nots as normal, and the start/stop button works ok, but the sequencer speed runs very slow and erratic, if I enter a 4 note sequence the notes are played back non equidistant, but when I sync it with cubase it runs fine matching the tempo nicely.
Do you guys think it might just be a broken slider pot?. and are these pots easily sourced? or is there a replacement i could use?.

any help here would be greatly appreciated. thanks fellas.

--- In korgpolyex@yahoogroups.com, "p" <peteput@...> wrote:
>
> hey chaps. i recently bought this poly-800 mk1 ( my 3rd!) and it arrived with a non working SEQ Speed slider, sliding it up and down makes no difference to the seq speed. is this a common problem and is it fixable?
>
> thanks
>

yes the black wire is there and soldered to a resistor. the solder was a little loose so i re-soldered it, no change. it seems that sometimes the sequencer wont run at all from the start/stop button, which functions fine in seq edit mode.

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
> there is a black earth wire that runs to the slider board. If that wire is
> missing or broken, the sequencer will run slow.
>
> Is it there and is it connected to ground (with a screw to the main steel
> bracket that runs the length of the keyboard)?
>
>
>
>
> ________________________________
> From: p <peteput@...>
> To: korgpolyex@yahoogroups.com
> Sent: Sun, July 11, 2010 6:59:33 AM
> Subject: [korgpolyex] Re: poly-800 mk1 seq speed slider broken
>
>
> hello polyfans. great group by the way :)
>
> So I've had my poly800 apart and couldnt find any obvious flaws regarding the
> non-working speed fader, I can input nots as normal, and the start/stop button
> works ok, but the sequencer speed runs very slow and erratic, if I enter a 4
> note sequence the notes are played back non equidistant, but when I sync it
> with cubase it runs fine matching the tempo nicely.
> Do you guys think it might just be a broken slider pot?. and are these pots
> easily sourced? or is there a replacement i could use?.
>
>
> any help here would be greatly appreciated. thanks fellas.
>
> --- In korgpolyex@yahoogroups.com, "p" <peteput@> wrote:
> >
> > hey chaps. i recently bought this poly-800 mk1 ( my 3rd!) and it arrived
> >with a non working SEQ Speed slider, sliding it up and down makes no difference
> >to the seq speed. is this a common problem and is it fixable?
> >
> > thanks
> >
>

Hello again...

I've tried new earth wires, tried new earth points...now i'm wondering if the internal battery might be low on power and would this affect the sequencer speed?, on further investigation the speed slider does have an effect, but it is so slight...it goes from slow to very slow, and still the timing isnt regular.....could this mean i need a new KLM597b board? does anyone have a spare they would be willing to sell? or possibly a replacement ic chip whichever it is that has the sequencer clock...I dearly love this synth and the sequencer is a major part of its appeal for me....like i mentioned in an earlier post the sequencer runs fine when synced to midi.

any further thoughts would be massively appreciated.

thanks for all your help polyfans!

--- In korgpolyex@yahoogroups.com, "p" <peteput@...> wrote:
>
> yes the black wire is there and soldered to a resistor. the solder was a little loose so i re-soldered it, no change. it seems that sometimes the sequencer wont run at all from the start/stop button, which functions fine in seq edit mode.
>
> --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> >
> > there is a black earth wire that runs to the slider board. If that wire is
> > missing or broken, the sequencer will run slow.
> >
> > Is it there and is it connected to ground (with a screw to the main steel
> > bracket that runs the length of the keyboard)?
> >
> >
> >
> >
> > ________________________________
> > From: p <peteput@>
> > To: korgpolyex@yahoogroups.com
> > Sent: Sun, July 11, 2010 6:59:33 AM
> > Subject: [korgpolyex] Re: poly-800 mk1 seq speed slider broken
> >
> >
> > hello polyfans. great group by the way :)
> >
> > So I've had my poly800 apart and couldnt find any obvious flaws regarding the
> > non-working speed fader, I can input nots as normal, and the start/stop button
> > works ok, but the sequencer speed runs very slow and erratic, if I enter a 4
> > note sequence the notes are played back non equidistant, but when I sync it
> > with cubase it runs fine matching the tempo nicely.
> > Do you guys think it might just be a broken slider pot?. and are these pots
> > easily sourced? or is there a replacement i could use?.
> >
> >
> > any help here would be greatly appreciated. thanks fellas.
> >
> > --- In korgpolyex@yahoogroups.com, "p" <peteput@> wrote:
> > >
> > > hey chaps. i recently bought this poly-800 mk1 ( my 3rd!) and it arrived
> > >with a non working SEQ Speed slider, sliding it up and down makes no difference
> > >to the seq speed. is this a common problem and is it fixable?
> > >
> > > thanks
> > >
> >
>

p wrote:

> Hello again...
>
> I've tried new earth wires, tried new earth points...now i'm wondering if the internal battery might be low on power and would this affect the sequencer speed?, on further investigation the speed slider does have an effect, but it is so slight...it goes from slow to very slow, and still the timing isnt regular.....could this mean i need a new KLM597b board? does anyone have a spare they would be willing to sell? or possibly a replacement ic chip whichever it is that has the sequencer clock...I dearly love this synth and the sequencer is a major part of its appeal for me....like i mentioned in an earlier post the sequencer runs fine when synced to midi.
>

Have you checked that the pot works correctly? It's not going to be the
battery.

Gordon MM0YEQ

Hi thanks for the quick reply...no i havent checked...im not sure how to...any suggestions?

--- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@...> wrote:
>
> p wrote:
> > Hello again...
> >
> > I've tried new earth wires, tried new earth points...now i'm wondering if the internal battery might be low on power and would this affect the sequencer speed?, on further investigation the speed slider does have an effect, but it is so slight...it goes from slow to very slow, and still the timing isnt regular.....could this mean i need a new KLM597b board? does anyone have a spare they would be willing to sell? or possibly a replacement ic chip whichever it is that has the sequencer clock...I dearly love this synth and the sequencer is a major part of its appeal for me....like i mentioned in an earlier post the sequencer runs fine when synced to midi.
> >
>
> Have you checked that the pot works correctly? It's not going to be the
> battery.
>
> Gordon MM0YEQ
>

Hi Pete,

the problem is more likely NOT the actual clock circuit itself (found on the
main board using half of IC36 and half of IC28 and sundry other discreet
components). For details of that circuit see section "4" on the main circuit
schematic in the files section.

More likely is that there is a problem with the speed slider pot itself or the
the connector CN2.

The annoying part of this is that the service manual doesn't include an exact
schematic diagram of the speed pot wired into the clock circuit.

So you will need to do some tracing yourself. But I would start by checking that

the slider pot runs through a range of resistance first. You will need a
multimeter for that. If you don't have a multimeter then you will need to find
someone that does or else go buy one.

And then I would check to see that the three wires going from the main board to
the display board via CN2 are not broken. Make sure all thee connections have
continuity.

Mike

i have access to a multimeter, perhaps i could use this to check the pot with a little help from you guys? as i have little experience using one.

--- In korgpolyex@yahoogroups.com, "p" <peteput@...> wrote:
>
> Hi thanks for the quick reply...no i havent checked...im not sure how to...any suggestions?
>
> --- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@> wrote:
> >
> > p wrote:
> > > Hello again...
> > >
> > > I've tried new earth wires, tried new earth points...now i'm wondering if the internal battery might be low on power and would this affect the sequencer speed?, on further investigation the speed slider does have an effect, but it is so slight...it goes from slow to very slow, and still the timing isnt regular.....could this mean i need a new KLM597b board? does anyone have a spare they would be willing to sell? or possibly a replacement ic chip whichever it is that has the sequencer clock...I dearly love this synth and the sequencer is a major part of its appeal for me....like i mentioned in an earlier post the sequencer runs fine when synced to midi.
> > >
> >
> > Have you checked that the pot works correctly? It's not going to be the
> > battery.
> >
> > Gordon MM0YEQ
> >
>

Hi Michael,

thanks for the reply, i didnt see this until after i posted my last one...
one thing im not sure about is which settings on the multimeter to use and what the resistance values should be.

pete.

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
>
>
> Hi Pete,
>
> the problem is more likely NOT the actual clock circuit itself (found on the
> main board using half of IC36 and half of IC28 and sundry other discreet
> components). For details of that circuit see section "4" on the main circuit
> schematic in the files section.
>
> More likely is that there is a problem with the speed slider pot itself or the
> the connector CN2.
>
> The annoying part of this is that the service manual doesn't include an exact
> schematic diagram of the speed pot wired into the clock circuit.
>
> So you will need to do some tracing yourself. But I would start by checking that
>
> the slider pot runs through a range of resistance first. You will need a
> multimeter for that. If you don't have a multimeter then you will need to find
> someone that does or else go buy one.
>
> And then I would check to see that the three wires going from the main board to
> the display board via CN2 are not broken. Make sure all thee connections have
> continuity.
>
> Mike
>

Hi. So i took her apart again, resoldered all the wires from KLM597-b. and no change again. took it apart once more and noticed inside the speed pot the contact seemed much more dirty than the bend rate and tune pots. so after a better clean with Servisol Super10 and a vigorous slider session things improved dramaticallly though not 100%, now after an hour or 2 things have gone back to norman slow and slower, should i take apart the pot and give it a thorough clean? is this possible without removing it from the board?.


thanks so much for all your help...i'd be lost otherwise.

pete.

--- In korgpolyex@yahoogroups.com, "p" <peteput@...> wrote:
>
> Hi Michael,
>
> thanks for the reply, i didnt see this until after i posted my last one...
> one thing im not sure about is which settings on the multimeter to use and what the resistance values should be.
>
> pete.
>
>
>
> --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> >
> >
> >
> > Hi Pete,
> >
> > the problem is more likely NOT the actual clock circuit itself (found on the
> > main board using half of IC36 and half of IC28 and sundry other discreet
> > components). For details of that circuit see section "4" on the main circuit
> > schematic in the files section.
> >
> > More likely is that there is a problem with the speed slider pot itself or the
> > the connector CN2.
> >
> > The annoying part of this is that the service manual doesn't include an exact
> > schematic diagram of the speed pot wired into the clock circuit.
> >
> > So you will need to do some tracing yourself. But I would start by checking that
> >
> > the slider pot runs through a range of resistance first. You will need a
> > multimeter for that. If you don't have a multimeter then you will need to find
> > someone that does or else go buy one.
> >
> > And then I would check to see that the three wires going from the main board to
> > the display board via CN2 are not broken. Make sure all thee connections have
> > continuity.
> >
> > Mike
> >
>

Ok so the track inside the pot has small "blank spots" towards the top and bottom, are these tracks actually on the pcb or the pot itself? i have been trying to find a 100k lin pot @45mm with a 35mm throw but so far nothing doing, do you know where i could find one?

poly love
pete.

--- In korgpolyex@yahoogroups.com, "p" <peteput@...> wrote:
>
> Hi. So i took her apart again, resoldered all the wires from KLM597-b. and no change again. took it apart once more and noticed inside the speed pot the contact seemed much more dirty than the bend rate and tune pots. so after a better clean with Servisol Super10 and a vigorous slider session things improved dramaticallly though not 100%, now after an hour or 2 things have gone back to norman slow and slower, should i take apart the pot and give it a thorough clean? is this possible without removing it from the board?.
>
>
> thanks so much for all your help...i'd be lost otherwise.
>
> pete.
>
> --- In korgpolyex@yahoogroups.com, "p" <peteput@> wrote:
> >
> > Hi Michael,
> >
> > thanks for the reply, i didnt see this until after i posted my last one...
> > one thing im not sure about is which settings on the multimeter to use and what the resistance values should be.
> >
> > pete.
> >
> >
> >
> > --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> > >
> > >
> > >
> > > Hi Pete,
> > >
> > > the problem is more likely NOT the actual clock circuit itself (found on the
> > > main board using half of IC36 and half of IC28 and sundry other discreet
> > > components). For details of that circuit see section "4" on the main circuit
> > > schematic in the files section.
> > >
> > > More likely is that there is a problem with the speed slider pot itself or the
> > > the connector CN2.
> > >
> > > The annoying part of this is that the service manual doesn't include an exact
> > > schematic diagram of the speed pot wired into the clock circuit.
> > >
> > > So you will need to do some tracing yourself. But I would start by checking that
> > >
> > > the slider pot runs through a range of resistance first. You will need a
> > > multimeter for that. If you don't have a multimeter then you will need to find
> > > someone that does or else go buy one.
> > >
> > > And then I would check to see that the three wires going from the main board to
> > > the display board via CN2 are not broken. Make sure all thee connections have
> > > continuity.
> > >
> > > Mike
> > >
> >
>

Great! thanks Mike. are you certain these will work? have you used them before?
pete.

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
> http://futurlec.com/PotSliding.shtml
>
>
>
>
> ________________________________
> From: p <peteput@...>
> To: korgpolyex@yahoogroups.com
> Sent: Sun, September 19, 2010 12:30:10 PM
> Subject: [korgpolyex] Re: poly-800 mk1 seq speed slider broken
>
>
> Ok so the track inside the pot has small "blank spots" towards the top and
> bottom, are these tracks actually on the pcb or the pot itself? i have been
> trying to find a 100k lin pot @45mm with a 35mm throw but so far nothing doing,
> do you know where i could find one?
>
> poly love
> pete.
>
> --- In korgpolyex@yahoogroups.com, "p" <peteput@> wrote:
> >
> > Hi. So i took her apart again, resoldered all the wires from KLM597-b. and no
> >change again. took it apart once more and noticed inside the speed pot the
> >contact seemed much more dirty than the bend rate and tune pots. so after a
> >better clean with Servisol Super10 and a vigorous slider session things improved
> >dramaticallly though not 100%, now after an hour or 2 things have gone back to
> >norman slow and slower, should i take apart the pot and give it a thorough
> >clean? is this possible without removing it from the board?.
> >
> >
> > thanks so much for all your help...i'd be lost otherwise.
> >
> > pete.
> >
> > --- In korgpolyex@yahoogroups.com, "p" <peteput@> wrote:
> > >
> > > Hi Michael,
> > >
> > > thanks for the reply, i didnt see this until after i posted my last one...
> > > one thing im not sure about is which settings on the multimeter to use and
> >what the resistance values should be.
> > >
> > > pete.
> > >
> > >
> > >
> > > --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@> wrote:
> > > >
> > > >
> > > >
> > > > Hi Pete,
> > > >
> > > > the problem is more likely NOT the actual clock circuit itself (found on
> >the
> >
> > > > main board using half of IC36 and half of IC28 and sundry other discreet
> > > > components). For details of that circuit see section "4" on the main
> >circuit
> >
> > > > schematic in the files section.
> > > >
> > > > More likely is that there is a problem with the speed slider pot itself or
> >the
> >
> > > > the connector CN2.
> > > >
> > > > The annoying part of this is that the service manual doesn't include an
> >exact
> >
> > > > schematic diagram of the speed pot wired into the clock circuit.
> > > >
> > > > So you will need to do some tracing yourself. But I would start by checking
> >that
> >
> > > >
> > > > the slider pot runs through a range of resistance first. You will need a
> > > > multimeter for that. If you don't have a multimeter then you will need to
> >find
> >
> > > > someone that does or else go buy one.
> > > >
> > > > And then I would check to see that the three wires going from the main
> >board to
> >
> > > > the display board via CN2 are not broken. Make sure all thee connections
> >have
> >
> > > > continuity.
> > > >
> > > > Mike
> > > >
> > >
> >
>