Discussion about the Korg PolySix synthesizer

I bought my PolySix a few months ago and had to have the battery and 
IC31 replaced and a few tracks re-wired.  It now sounds fantastic, 
but there are a couple of problems.

First, when I turn it on, there is no sound available except a very 
low-frequency 'bloop'. I have to press the 'Manual' button and 
twiddle a few knobs to start getting a proper sound.  Is this 
normal?  I would have thought it would have some recognisable patch 
on power-up.

Also, the write-to-memory doesn't work well.  If I write a patch, 
then select another patch, then back to the new patch, the sound is 
nothing like what I thought I stored.  Presumably there is another 
chip somewhere that needs to be replaced.  Is this a common problem 
with an easy fix?

Thanks, folks.

Hi,

you managed it to replace the IC\ufffds? I\ufffdve done it 10 Times and it won\ufffdt
work-program buttons are o.k., but no sound and no reaction from the
knobs (i\ufffdve also changed the A/D-Converter which SHOULD manage those
functions)...

Sh*t, i have TWO Polysix defect bought and BOTH would need a new
Mainboard (was it KLM-367?). Korg doesn\ufffdt produce it anymore, i found
noone who can really repair those two defect boards-i have no plan if it
is a broken wire, a defect IC, maybe the main processor is defect...so,
now i have two Polysix and i never heard a tone from them-strange, eh?

Do you know a source for replacement-parts? 

Greetings

Stef


reidar_oz <reidar@jorgensen.com> schrieb am 05.12.2002, 04:13:55:

> I bought my PolySix a few months ago and had to have the battery and 
> IC31 replaced and a few tracks re-wired.  It now sounds fantastic, 
> but there are a couple of problems.
> 
> First, when I turn it on, there is no sound available except a very 
> low-frequency 'bloop'. I have to press the 'Manual' button and 
> twiddle a few knobs to start getting a proper sound.  Is this 
> normal?  I would have thought it would have some recognisable patch 
> on power-up.
> 
> Also, the write-to-memory doesn't work well.  If I write a patch, 
> then select another patch, then back to the new patch, the sound is 
> nothing like what I thought I stored.  Presumably there is another 
> chip somewhere that needs to be replaced.  Is this a common problem 
> with an easy fix?
> 
> Thanks, folks.
> 
> 
> To unsubscribe from this group, send an email to:
> PolySix-unsubscribe@egroups.com
> 
> PolySix "Digiest" Page: http://www.ing.umu.se/~me96kus/p6digi.html
>  
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

I would suspect the actual RAM chip has gone bad.  It is IC32.  I've had 
to replace the RAM chip on more than one rebuilt KLM-367 board.

  It is listed as a Toshiba TC5514-APL3, but there are a few equivalent 
part numbers that drop-in as well.  In the USA, I get them from 
www.jameco.com, Jameco stock# 43238.  The part they sell is an Intersil 
HM6514, but it works just fine as a direct replacement.  
See http://www.jameco.com/Jameco/Products/ProdDS/43238.pdf

  These also replace the hard-to-obtain Nec uPD444c (same sort of RAM 
chip).

  It is also possible that the RAM addressing latches, IC24 and IC26, are 
bad or otherwise a trace involving them is corroded. 

Crow
/**/

On Thu, 5 Dec 2002, reidar_oz wrote:

> I bought my PolySix a few months ago and had to have the battery and
> IC31 replaced and a few tracks re-wired.  It now sounds fantastic, but
> there are a couple of problems.
> 
> First, when I turn it on, there is no sound available except a very
> low-frequency 'bloop'. I have to press the 'Manual' button and twiddle a
> few knobs to start getting a proper sound.  Is this normal?  I would
> have thought it would have some recognisable patch on power-up.
> 
> Also, the write-to-memory doesn't work well.  If I write a patch, then
> select another patch, then back to the new patch, the sound is nothing
> like what I thought I stored.  Presumably there is another chip
> somewhere that needs to be replaced.  Is this a common problem with an
> easy fix?