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Poly 800 problems, IC

Poly 800 problems, IC

2008-11-24 by tyrone_topheavy

Hey all.

I just rec'd a Poly 800 from "that auction place". In the past, I've 
relaced the battery and uploaded the new sounds from my PC through 
the tape jack, and I assumed this would be the problem with this one.

First, this is an early model, so no battery.

Second, I looked at the IC NJM2069D3004, and noticed it appeared to 
be installed backwards, as it's "key" (the indentaion on the chip) 
was opposite of all the other ICs on the board. So, I pulled it, and 
observed some of the legs were missing or bent. Someones obviously 
been here before me.

Also, I noticed several jumpers on the board that seem to be mods or 
repairs. IC 24 has two of it's pins jumpered (20 to 23) IC 22 has 
been jumpered to IC 24, and two capicitors are also jumpered (C95 to 
C97).Lastly, the wiring harness that connects the main PCB to the 
smaller brown one under the front panel appears to have had some 
modification to it. Pins 1,2,3 and 4 on CN6A seem to have been 
spliced.

I know the guy that makes the Hawk kits hangs out here, and you guys 
know more about this synth than anyone. Do these mods look farmiliar 
to you ? Can you tell me what someone was trying to do ? Is it 
reversable ? Can I just break the jumpers ?

Also, since the pins on the IC are bent/missingm are there 
replacements avaialable ? I've read elsewhere the EPROM can be 
burned, and the data is on the net, but I have neither the equipment, 
expertise not patience to burn my on ICs.

Or, is this a candidate for the trash pile ? I could always part it 
out, I guess...

Thanks in advance for your help. This is a neat little grouop you 
have going here.

Re: [korgpolyex] Poly 800 problems, IC

2008-11-24 by Gordon JC Pearce MM3YEQ

tyrone_topheavy wrote:
> Hey all.
> 
> I just rec'd a Poly 800 from "that auction place". In the past, I've 
> relaced the battery and uploaded the new sounds from my PC through 
> the tape jack, and I assumed this would be the problem with this one.
> 
> First, this is an early model, so no battery.
> 
> Second, I looked at the IC NJM2069D3004, and noticed it appeared to 
> be installed backwards, as it's "key" (the indentaion on the chip) 
> was opposite of all the other ICs on the board. So, I pulled it, and 
> observed some of the legs were missing or bent. Someones obviously 
> been here before me.

That's the filter IC.  If there's the fat "stub" of the leg left, you 
could try soldering a bit of resistor lead on as a "wooden leg" for it ;-)

The wire links you talk about may be repairs to damaged tracks on the 
board, possibly caused by the nicad leaking corrosive goo.

Gordon

Re: [korgpolyex] Poly 800 problems, IC

2008-11-24 by Tyrone Lumley

Good idea, I wouldn't have thought of that. It worked fine on one leg.
 
Unfortunately, another leg is busted all the way up past the fat part.
 
Looks like I got me a 75 dollar MIDI controller.

--- On Mon, 11/24/08, Gordon JC Pearce MM3YEQ <gordon@...> wrote:
Show quoted textHide quoted text
From: Gordon JC Pearce MM3YEQ <gordon@...>
Subject: Re: [korgpolyex] Poly 800 problems, IC
To: korgpolyex@yahoogroups.com
Date: Monday, November 24, 2008, 3:07 PM






tyrone_topheavy wrote:
> Hey all.
> 
> I just rec'd a Poly 800 from "that auction place". In the past, I've 
> relaced the battery and uploaded the new sounds from my PC through 
> the tape jack, and I assumed this would be the problem with this one.
> 
> First, this is an early model, so no battery.
> 
> Second, I looked at the IC NJM2069D3004, and noticed it appeared to 
> be installed backwards, as it's "key" (the indentaion on the chip) 
> was opposite of all the other ICs on the board. So, I pulled it, and 
> observed some of the legs were missing or bent. Someones obviously 
> been here before me.

That's the filter IC. If there's the fat "stub" of the leg left, you 
could try soldering a bit of resistor lead on as a "wooden leg" for it ;-)

The wire links you talk about may be repairs to damaged tracks on the 
board, possibly caused by the nicad leaking corrosive goo.

Gordon

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Atom Smasher

On Mon, 24 Nov 2008, Tyrone Lumley wrote:

> Good idea, I wouldn't have thought of that. It worked fine on one leg.
> 
> Unfortunately, another leg is busted all the way up past the fat part.
============

IFAIK, those chips are no more. it seems like you have nothing to lose, so 
you might want to try filing away some of the resin from around the busted 
leg, and try to get enough exposed metal that you can solder something to 
it. another trick that might work is inspired by the SMT DIYers... put 
some solder paste on the joint with a "peg leg", hold it together with 
stainless steel locking forceps (or some other stainless steel tool), and 
put it in a toaster over; heat it until the solder starts to flow, then 
turn off the toaster and let it cool.


> Looks like I got me a 75 dollar MIDI controller.
==============

was it "as is"? or "powers up but i have no way to test it"?


-- 
         ...atom

  ________________________
  http://atom.smasher.org/
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"The most potent weapon in the hands of the
 	 oppressor is the mind of the oppressed."
 		-- Steve Biko

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Tyrone Lumley

Hey thanks for writing back !
 
No, the guy was honest. As is, he was adimant about that. I just thought I'd get lucky. The last couple I bought had a bad battery, or even in one case the tape switch was activated and they thought it was broken. I'm bound to eat one every now and then.
 
Anyway, I have the IC back in, minus one leg. It took the tape .wav file, and the factory presets all match the parameters on the spreadsheet in the files section.
 
However, DCO1 is making nothing but white noise. On patches with only one DCO I get nothing, and the ones that use two work, but there is background hiss. Do you think it has something to do with that bad leg ?
 
I'll try exposing the metal using mechanical means. My mind was already there, but stopped short.
 
Any other ideas on what would cause DCO1 to not produce anything but white noise ?


--- On Mon, 11/24/08, Atom Smasher <atom@...> wrote:
Show quoted textHide quoted text
From: Atom Smasher <atom@...>
Subject: Re: [korgpolyex] Poly 800 problems, IC
To: korgpolyex@yahoogroups.com
Date: Monday, November 24, 2008, 10:52 PM






On Mon, 24 Nov 2008, Tyrone Lumley wrote:

> Good idea, I wouldn't have thought of that. It worked fine on one leg.
> 
> Unfortunately, another leg is busted all the way up past the fat part.
============

IFAIK, those chips are no more. it seems like you have nothing to lose, so 
you might want to try filing away some of the resin from around the busted 
leg, and try to get enough exposed metal that you can solder something to 
it. another trick that might work is inspired by the SMT DIYers... put 
some solder paste on the joint with a "peg leg", hold it together with 
stainless steel locking forceps (or some other stainless steel tool), and 
put it in a toaster over; heat it until the solder starts to flow, then 
turn off the toaster and let it cool.

> Looks like I got me a 75 dollar MIDI controller.
============ ==

was it "as is"? or "powers up but i have no way to test it"?

-- 
...atom

____________ _________ ___
http://atom. smasher.org/
762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
------------ --------- --------- --------- --------- -

"The most potent weapon in the hands of the
oppressor is the mind of the oppressed."
-- Steve Biko

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Gordon JC Pearce MM3YEQ

Tyrone Lumley wrote:
> Good idea, I wouldn't have thought of that. It worked fine on one leg.
>  
> Unfortunately, another leg is busted all the way up past the fat part.
>  
> Looks like I got me a 75 dollar MIDI controller.
> 

There are two things you can try.  You could carefully cut back the 
epoxy with a dremel until you've got enough leg to solder a new pin to, 
or you could see if that pin is even important.  There's probably 
*someone* out there with a knackered Poly-800 or similar Korg synth that 
can give you a chip, or you could even just bypass it and not have any 
filter at all for a lovely chiptune-like effect.

If you were really keen you could just build a filter on protoboard and 
add that in.

Gordon

Re: Poly 800 problems, IC

2008-11-25 by narfman96

Here is some info for the NJM2069:
 KORG NJM2069
Pin# Function
1 Audio In GND (GND)
2 Mixer Signal 1 Level CV In
3 Mixer Signal 2 Level CV In
4 VCF Resonance CV In
5 VCF 12dB/oct Audio Out
6 VCF 24dB/oct Audio Out
7 VCA Signal In
8 VCA Level CV Log In
9 VCA Level CV Lin In
10 VCA Signal Out
11 Vss (GND)
12 -Vee (-5v)
13 VCF Cutoff CV Lin In
14 VCF Cutoff CV Log In
15 VCF cap C4
16 VCF cap C3
17 VCF cap C2
18 VCF cap C1
19 VCF Ext Audio In
20 Mixer Signal 2 In
21 Mixer Signal 1 In
22 +Vcc (+5v)
Which pin is busted? 2,3 or 20,21 Not sure if this can disable DCO1 
but it sure looks like it could??? 
I've had good luck soldering to busted pins even if they were flush 
with the side of the chip. Just remember the heat will now be much 
closer to the inner workings. I also have the pdf datasheet for the 
NJM2069 around here somewhere. 
Good Luck, Fran

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Michael Hawkins

Ty,

We should assess the situation before making any attempts at repair of it.

Since the board is without the battery it is most likely an early version of Poly. What is the serial number on the case?

In early versions Korg themselves fitted quite a few jumpers to the main board.

Are the jumpers that you see clear plastic with a solid silver core? If they are, they're probably Korg installed.

And before you go doing anything to the filter chip, which pins are damaged?

Mike

Show quoted textHide quoted text
From: tyrone_topheavy
To: korgpolyex@yahoogroups.com
Sent: Monday, November 24, 2008 6:04:29 PM
Subject: [korgpolyex] Poly 800 problems, IC

Hey all.

I just rec'd a Poly 800 from "that auction place". In the past, I've
relaced the battery and uploaded the new sounds from my PC through
the tape jack, and I assumed this would be the problem with this one.

First, this is an early model, so no battery.

Second, I looked at the IC NJM2069D3004, and noticed it appeared to
be installed backwards, as it's "key" (the indentaion on the chip)
was opposite of all the other ICs on the board. So, I pulled it, and
observed some of the legs were missing or bent. Someones obviously
been here before me.

Also, I noticed several jumpers on the board that seem to be mods or
repairs. IC 24 has two of it's pins jumpered (20 to 23) IC 22 has
been jumpered to IC 24, and two capicitors are also jumpered (C95 to
C97).Lastly, the wiring harness that connects the main PCB to the
smaller brown one under the front panel appears to have had some
modification to it. Pins 1,2,3 and 4 on CN6A seem to have been
spliced.

I know the guy that makes the Hawk kits hangs out here, and you guys
know more about this synth than anyone. Do these mods look farmiliar
to you ? Can you tell me what someone was trying to do ? Is it
reversable ? Can I just break the jumpers ?

Also, since the pins on the IC are bent/missingm are there
replacements avaialable ? I've read elsewhere the EPROM can be
burned, and the data is on the net, but I have neither the equipment,
expertise not patience to burn my on ICs.

Or, is this a candidate for the trash pile ? I could always part it
out, I guess...

Thanks in advance for your help. This is a neat little grouop you
have going here.


Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by David Mochen

Hi there,
I keep reading messages like "got this poly 800 for 0.02 cents" and the like and I really can't help turning green with envy! Here in Argentina people will sell their second (or third, fourth, whatever) hand Poly's for sums equivalent to US$ 300 >:-(
check this one
AR$ 900 bucks = ~US$ 281, current exchange rates.
sighs...
Dave
PS: note the "Polly 800"... brings back memories of Auntie Polly in Tom Sayer hahaha...
Show quoted textHide quoted text
----- Original Message -----
Sent: Monday, November 24, 2008 8:04 PM
Subject: [korgpolyex] Poly 800 problems, IC

Hey all.

I just rec'd a Poly 800 from "that auction place". In the past, I've
relaced the battery and uploaded the new sounds from my PC through
the tape jack, and I assumed this would be the problem with this one.

First, this is an early model, so no battery.

Second, I looked at the IC NJM2069D3004, and noticed it appeared to
be installed backwards, as it's "key" (the indentaion on the chip)
was opposite of all the other ICs on the board. So, I pulled it, and
observed some of the legs were missing or bent. Someones obviously
been here before me.

Also, I noticed several jumpers on the board that seem to be mods or
repairs. IC 24 has two of it's pins jumpered (20 to 23) IC 22 has
been jumpered to IC 24, and two capicitors are also jumpered (C95 to
C97).Lastly, the wiring harness that connects the main PCB to the
smaller brown one under the front panel appears to have had some
modification to it. Pins 1,2,3 and 4 on CN6A seem to have been
spliced.

I know the guy that makes the Hawk kits hangs out here, and you guys
know more about this synth than anyone. Do these mods look farmiliar
to you ? Can you tell me what someone was trying to do ? Is it
reversable ? Can I just break the jumpers ?

Also, since the pins on the IC are bent/missingm are there
replacements avaialable ? I've read elsewhere the EPROM can be
burned, and the data is on the net, but I have neither the equipment,
expertise not patience to burn my on ICs.

Or, is this a candidate for the trash pile ? I could always part it
out, I guess...

Thanks in advance for your help. This is a neat little grouop you
have going here.

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Tyrone Lumley

Wow, the Man himself responds !!!! I feel special ;)
 
Yes, solid core wire with clear sleeving, which means factory ? Good !
 
I already did the battery mod, it was easy. She remebers her patches now. But yeah, it seems to be an eraly model with no internal battery. SN is 009958.
 
The pin that has no leg anymore is the last one on the bottom left hand side, if the key is oriented towards the top (away from you). I don't have a data sheet so I can't tell you what number it is. 

--- On Tue, 11/25/08, Michael Hawkins <korgpolyex800@...> wrote:
Show quoted textHide quoted text
From: Michael Hawkins <korgpolyex800@yahoo.com>
Subject: Re: [korgpolyex] Poly 800 problems, IC
To: korgpolyex@yahoogroups.com
Date: Tuesday, November 25, 2008, 5:10 AM








Ty,

We should assess the situation before making any attempts at repair of it.

Since the board is without the battery it is most likely an early version of Poly. What is the serial number on the case?

In early versions Korg themselves fitted quite a few jumpers to the main board.

Are the jumpers that you see clear plastic with a solid silver core? If they are, they're probably Korg installed.

And before you go doing anything to the filter chip, which pins are damaged?

Mike





From: tyrone_topheavy <tyrone_topheavy@ yahoo.com>
To: korgpolyex@yahoogro ups.com
Sent: Monday, November 24, 2008 6:04:29 PM
Subject: [korgpolyex] Poly 800 problems, IC



Hey all.

I just rec'd a Poly 800 from "that auction place". In the past, I've 
relaced the battery and uploaded the new sounds from my PC through 
the tape jack, and I assumed this would be the problem with this one.

First, this is an early model, so no battery.

Second, I looked at the IC NJM2069D3004, and noticed it appeared to 
be installed backwards, as it's "key" (the indentaion on the chip) 
was opposite of all the other ICs on the board. So, I pulled it, and 
observed some of the legs were missing or bent. Someones obviously 
been here before me.

Also, I noticed several jumpers on the board that seem to be mods or 
repairs. IC 24 has two of it's pins jumpered (20 to 23) IC 22 has 
been jumpered to IC 24, and two capicitors are also jumpered (C95 to 
C97).Lastly, the wiring harness that connects the main PCB to the 
smaller brown one under the front panel appears to have had some 
modification to it. Pins 1,2,3 and 4 on CN6A seem to have been 
spliced.

I know the guy that makes the Hawk kits hangs out here, and you guys 
know more about this synth than anyone. Do these mods look farmiliar 
to you ? Can you tell me what someone was trying to do ? Is it 
reversable ? Can I just break the jumpers ?

Also, since the pins on the IC are bent/missingm are there 
replacements avaialable ? I've read elsewhere the EPROM can be 
burned, and the data is on the net, but I have neither the equipment, 
expertise not patience to burn my on ICs.

Or, is this a candidate for the trash pile ? I could always part it 
out, I guess...

Thanks in advance for your help. This is a neat little grouop you 
have going here.

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Michael Hawkins

No, I feel special !

Yes, I remember opening up my first early Poly-800 and seeing all the sleeved jumper wires and thinking - what is that?

So I think you might be OK there.

But your filter chip is another story. You can't have an NJM2069 missing pins.

Bottom left from the notch would most likely be the ground pin (pin 11).

Now the interesting thing is that there are two ground pins on the NJM2069.

So I am not certain that you actually HAVE to have both.

Someone needs to take their filter chip out and measure the ohm's between pin 1 and pin 11. If the multimeter shows a short then it's possible that you can do without pin 11. If it shows an open then you're going to have to get your dremmel out.

Is anyone near their Poly right now with a multimeter handy?

Mike.


________________________________
Show quoted textHide quoted text
From: Tyrone Lumley <tyrone_topheavy@...>
To: korgpolyex@yahoogroups.com
Sent: Tuesday, November 25, 2008 11:53:45 AM
Subject: Re: [korgpolyex] Poly 800 problems, IC


Wow, the Man himself responds !!!! I feel special ;)
 
Yes, solid core wire with clear sleeving, which means factory ? Good !
 
I already did the battery mod, it was easy. She remebers her patches now. But yeah, it seems to be an eraly model with no internal battery. SN is 009958.
 
The pin that has no leg anymore is the last one on the bottom left hand side, if the key is oriented towards the top (away from you). I don't have a data sheet so I can't tell you what number it is. 

--- On Tue, 11/25/08, Michael Hawkins <korgpolyex800@ yahoo.com> wrote:

From: Michael Hawkins <korgpolyex800@ yahoo.com>
Subject: Re: [korgpolyex] Poly 800 problems, IC
To: korgpolyex@yahoogro ups.com
Date: Tuesday, November 25, 2008, 5:10 AM


Ty,

We should assess the situation before making any attempts at repair of it.

Since the board is without the battery it is most likely an early version of Poly. What is the serial number on the case?

In early versions Korg themselves fitted quite a few jumpers to the main board.

Are the jumpers that you see clear plastic with a solid silver core? If they are, they're probably Korg installed.

And before you go doing anything to the filter chip, which pins are damaged?

Mike




________________________________
 From: tyrone_topheavy <tyrone_topheavy@ yahoo.com>
To: korgpolyex@yahoogro ups.com
Sent: Monday, November 24, 2008 6:04:29 PM
Subject: [korgpolyex] Poly 800 problems, IC


Hey all.

I just rec'd a Poly 800 from "that auction place". In the past, I've 
relaced the battery and uploaded the new sounds from my PC through 
the tape jack, and I assumed this would be the problem with this one.

First, this is an early model, so no battery.

Second, I looked at the IC NJM2069D3004, and noticed it appeared to 
be installed backwards, as it's "key" (the indentaion on the chip) 
was opposite of all the other ICs on the board. So, I pulled it, and 
observed some of the legs were missing or bent. Someones obviously 
been here before me.

Also, I noticed several jumpers on the board that seem to be mods or 
repairs. IC 24 has two of it's pins jumpered (20 to 23) IC 22 has 
been jumpered to IC 24, and two capicitors are also jumpered (C95 to 
C97).Lastly, the wiring harness that connects the main PCB to the 
smaller brown one under the front panel appears to have had some 
modification to it. Pins 1,2,3 and 4 on CN6A seem to have been 
spliced.

I know the guy that makes the Hawk kits hangs out here, and you guys 
know more about this synth than anyone. Do these mods look farmiliar 
to you ? Can you tell me what someone was trying to do ? Is it 
reversable ? Can I just break the jumpers ?

Also, since the pins on the IC are bent/missingm are there 
replacements avaialable ? I've read elsewhere the EPROM can be 
burned, and the data is on the net, but I have neither the equipment, 
expertise not patience to burn my on ICs.

Or, is this a candidate for the trash pile ? I could always part it 
out, I guess...

Thanks in advance for your help. This is a neat little grouop you 
have going here.

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Alec Jahn

I got absolutely nothing between pin 1 and 11. To quote: KORG NJM2069 Pin# Function 1 Audio In GND (GND) 2 Mixer Signal 1 Level CV In 3 Mixer Signal 2 Level CV

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Michael Hawkins

Then Ty needs to get that dremmel out, I also have successfully used a jeweller's file to do the same job. Much slower of course.

Good luck Ty!

Show quoted textHide quoted text
From: Gordon JC Pearce MM3YEQ
To: korgpolyex@yahoogroups.com
Sent: Tuesday, November 25, 2008 2:32:23 PM
Subject: Re: [korgpolyex] Poly 800 problems, IC

Alec Jahn wrote:
> I got absolutely nothing between pin 1 and 11.
>

Same here.

Gordon


Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Tyrone Lumley

That's what I'll do then.
 
I did try some sample filing with various things I had lying around. That resin is TOUGH. Guess I'll borrow my friends dremmel.
 
Thanks for all the feedback. You guys know your stuff. This list seems more helpful and activer than other lists I belong to.

--- On Tue, 11/25/08, Michael Hawkins <korgpolyex800@...> wrote:
Show quoted textHide quoted text
From: Michael Hawkins <korgpolyex800@...>
Subject: Re: [korgpolyex] Poly 800 problems, IC
To: korgpolyex@yahoogroups.com
Date: Tuesday, November 25, 2008, 12:06 PM








Then Ty needs to get that dremmel out, I also have successfully used a jeweller's file to do the same job. Much slower of course.

Good luck Ty!





From: Gordon JC Pearce MM3YEQ <gordon@gjcp. net>
To: korgpolyex@yahoogro ups.com
Sent: Tuesday, November 25, 2008 2:32:23 PM
Subject: Re: [korgpolyex] Poly 800 problems, IC



Alec Jahn wrote:
> I got absolutely nothing between pin 1 and 11.
>

Same here.

Gordon

Re: [korgpolyex] Poly 800 problems, IC

2008-11-25 by Gordon JC Pearce MM3YEQ

Tyrone Lumley wrote:
> That's what I'll do then.
>  
> I did try some sample filing with various things I had lying around. 
> That resin is TOUGH. Guess I'll borrow my friends dremmel.

Exactly.  It's tough, not brittle.  It'll clog files in much the same 
way that aluminium or nylon does.

Gordon

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