I am not getting proper audio out of an old synthesizer. If I bypass
the board with the volume slider, everything works fine, but when the
audio runs through the board in question (Korg KLM-663-1), nothing
other than the occasional scratchy volume slider sound.

If necessary, I'd be willing to even pay a few bucks to any kind soul
who would take a few minutes time to point me in the right direction
of a fix (other than the obvious -- bad volume slider). The board
looks simple and straightforward, but I am a rank amateur when it
comes to tracing such a problem. I have both the service manual and a
couple of photos of the suspect board. If I recall right, audio
comes in on the connector on the right and leaves on the one on the
left (might have that reversed).

http://picasaweb.google.com/10293867...85/KorgDw8000#

I'm pretty certain the volume slider worked just fine, before I
replaced the battery for the patches because it did make noises,
albeit random ones. My multimeter also detects resistance change on
the slider when I move it up and down. One other strange thing I
noticed is that when the audio is re-routed, the detune slider doesn't
detune -- it seems to affect a parameter value -- a filter perhaps?
The slider that is supposed to change patch data also behaves
similarly -- no increase or decrease in patch or parameter value, but
instead a change in the parameter value.

On Tue, 16 Mar 2010 19:34:24 -0700 (PDT), evilaltima
wrote:

I am not getting proper audio out of an old synthesizer. If I bypass
the board with the volume slider, everything works fine, but when the
audio runs through the board in question (Korg KLM-663-1), nothing
other than the occasional scratchy volume slider sound.

If necessary, I'd be willing to even pay a few bucks to any kind soul
who would take a few minutes time to point me in the right direction
of a fix (other than the obvious -- bad volume slider). The board
looks simple and straightforward, but I am a rank amateur when it
comes to tracing such a problem. I have both the service manual and a
couple of photos of the suspect board. If I recall right, audio
comes in on the connector on the right and leaves on the one on the
left (might have that reversed).

http://picasaweb.google.com/10293867...85/KorgDw8000#

I'm pretty certain the volume slider worked just fine, before I
replaced the battery for the patches because it did make noises,
albeit random ones. My multimeter also detects resistance change on
the slider when I move it up and down. One other strange thing I
noticed is that when the audio is re-routed, the detune slider doesn't
detune -- it seems to affect a parameter value -- a filter perhaps?
The slider that is supposed to change patch data also behaves
similarly -- no increase or decrease in patch or parameter value, but
instead a change in the parameter value.

Is there a 'hard' reset for this unit? (The Kurzwiel 250 has a button
inside on the CPU board, for example). If yes, do a hard reset first.

Thanks for your time and suggestion Peter. It seemed such a simple
and elegant solution that could be easily overlooked that I was
excited to try it out. However, the only reset procedure in the
service manual I could find is the one to clear the memory for the
patches, which I had done a number of times while reloading SysEx
data. I tried it again for good measure (a couple of times even) and
still nothing but a scratchy slider sound is produced when keys are
pressed and the volume slider is moved.

It seems far fetched, but I suppose something could have happened to
the volume slider during my battery replacement. I've tried already
tried deoxit, but perhaps there a simple way I can bypass the volume
slider completely to test it other than replace it? IE, Can I insert
something into the circuit that sets the resistance open at full
volume? Again, please forgive my electronics naivete if that sounds
ignorant or uninformed, I'm an unemployed philosophy major by trade.

On Mar 17, 5:51*am, PeterD wrote:
On Tue, 16 Mar 2010 19:34:24 -0700 (PDT), evilaltima



wrote:
I am not getting proper audio out of an old synthesizer. *If I bypass
the board with the volume slider, everything works fine, but when the
audio runs through the board in question (Korg KLM-663-1), nothing
other than the occasional scratchy volume slider sound.

If necessary, I'd be willing to even pay a few bucks to any kind soul
who would take a few minutes time to point me in the right direction
of a fix (other than the obvious -- bad volume slider). *The board
looks simple and straightforward, but I am a rank amateur when it
comes to tracing such a problem. *I have both the service manual and a
couple of photos of the suspect board. * *If I recall right, audio
comes in on the connector on the right and leaves on the one on the
left (might have that reversed).

http://picasaweb.google.com/10293867...85/KorgDw8000#

I'm pretty certain the volume slider worked just fine, before I
replaced the battery for the patches because it did make noises,
albeit random ones. *My multimeter also detects resistance change on
the slider when I move it up and down. * One other strange thing I
noticed is that when the audio is re-routed, the detune slider doesn't
detune -- it seems to affect a parameter value -- a filter perhaps?
The slider that is supposed to change patch data also behaves
similarly -- no increase or decrease in patch or parameter value, but
instead a change in the parameter value.

Is there a 'hard' reset for this unit? (The Kurzwiel 250 has a button
inside on the CPU board, for example). If yes, do a hard reset first.

On Wed, 17 Mar 2010 13:25:23 -0700 (PDT), evilaltima
wrote:

Thanks for your time and suggestion Peter. It seemed such a simple
and elegant solution that could be easily overlooked that I was
excited to try it out. However, the only reset procedure in the
service manual I could find is the one to clear the memory for the
patches, which I had done a number of times while reloading SysEx
data. I tried it again for good measure (a couple of times even) and
still nothing but a scratchy slider sound is produced when keys are
pressed and the volume slider is moved.

It seems far fetched, but I suppose something could have happened to
the volume slider during my battery replacement. I've tried already
tried deoxit, but perhaps there a simple way I can bypass the volume
slider completely to test it other than replace it? IE, Can I insert
something into the circuit that sets the resistance open at full
volume? Again, please forgive my electronics naivete if that sounds
ignorant or uninformed, I'm an unemployed philosophy major by trade.


You could do that but the obvious thing is just to see if you can find
a replacement slider.

evilaltima wrote:
I am not getting proper audio out of an old synthesizer.\

Ya know, just from looking at the back side of the PC board
I'd suspect that the relay might be part of the problem.

You might be able to pull the plastic cover off of it and
manually operate it either up or down depending on which
way it's stuck.

Jeff



--
“Egotism is the anesthetic that dulls the pain of stupidity.”
Frank Leahy, Head coach, Notre Dame 1941-1954

http://www.stay-connect.com

Jeffrey D Angus wrote:
evilaltima wrote:
I am not getting proper audio out of an old synthesizer.\

Ya know, just from looking at the back side of the PC board
I'd suspect that the relay might be part of the problem.

You might be able to pull the plastic cover off of it and
manually operate it either up or down depending on which
way it's stuck.

Jeff

Yep, I've seen very similar relays in the old SAE equipment. Pop off the lid
of the relay and use a burnishing tool to clean the contacts. That should
fix it right up. In fact, before you even do that, just tap on the relay
with it powered up and see if the sound doesn't come back to normal for a
while. Of course watch what you're doing with the set powered on.

Good luck.
--
David Farber
David Farber's Service Center
L.A., CA

Thanks so much for the suggestions! I did initially think the relay
might be problematic, but it has always has made a clicking sound when
I powered it up. I still took the advice and cleaned it up a bit just
in case there was a contact issue. Still no luck.

Another interesting thing --as well as having no volume and strangely
behaving tuner slider, the arpeggiator slider also does nothing - just
like the volume. When functioning, the arpeggiator slider slows and
speeds up the red LED which correlates to the resistance of that
slider and the speed of the arpeggiator. However, even though I can
read it with my multimeter -- just like I can the volume slider, the
LED speed does not increase or decrease perhaps indicating a common
fault.

I'm at a loss to think what might be affecting the functionality of
all three of the sliders. I thought maybe the IC on the board might
have something to do with it, but looking at the PDF, although it
could potentially be a source of no volume, I don't think it would
affect the other two sliders.

http://pdf1.alldatasheet.com/datashe...HI/M5216L.html


Thanks again for the help!

On Mar 17, 7:16*pm, "David Farber" wrote:
Jeffrey D Angus wrote:
evilaltima wrote:
I am not getting proper audio out of an old synthesizer.\

Ya know, just from looking at the back side of the PC board
I'd suspect that the relay might be part of the problem.

You might be able to pull the plastic cover off of it and
manually operate it either up or down depending on which
way it's stuck.

Jeff

Yep, I've seen very similar relays in the old SAE equipment. Pop off the lid
of the relay and use a burnishing tool to clean the contacts. That should
fix it right up. In fact, before you even do that, just tap on the relay
with it powered up and see if the sound doesn't come back to normal for a
while. Of course watch what you're doing with the set powered on.

Good luck.
--
David Farber
David Farber's Service Center
L.A., CA

"evilaltima" wrote in message
...
I am not getting proper audio out of an old synthesizer. If I bypass
the board with the volume slider, everything works fine, but when the
audio runs through the board in question (Korg KLM-663-1), nothing
other than the occasional scratchy volume slider sound.

If necessary, I'd be willing to even pay a few bucks to any kind soul
who would take a few minutes time to point me in the right direction
of a fix (other than the obvious -- bad volume slider). The board
looks simple and straightforward, but I am a rank amateur when it
comes to tracing such a problem. I have both the service manual and a
couple of photos of the suspect board. If I recall right, audio
comes in on the connector on the right and leaves on the one on the
left (might have that reversed).

http://picasaweb.google.com/10293867...85/KorgDw8000#

I'm pretty certain the volume slider worked just fine, before I
replaced the battery for the patches because it did make noises,
albeit random ones. My multimeter also detects resistance change on
the slider when I move it up and down. One other strange thing I
noticed is that when the audio is re-routed, the detune slider doesn't
detune -- it seems to affect a parameter value -- a filter perhaps?
The slider that is supposed to change patch data also behaves
similarly -- no increase or decrease in patch or parameter value, but
instead a change in the parameter value.

Can you post a picture of the schematic?

Tom

Can you post a picture of the schematic?

Tom

The schematic is he

http://picasaweb.google.com/10293867...03595012399106

The entire service manual is he

http://www.pallium.com/bryan/dw/DW-8...ice_Manual.pdf

Thanks again to everyone who's tried to help.

Is there, by chance, a relay on that board, to prevent the power-on
pop from getting through to the amp?

If so, you might want to investigate that part. It is very common for
these to go bad and only let volume scratch through.