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Discussion about the Korg PolySix synthesizer

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Message

Re: [PolySix] EG and VCF not working after battery leakage

2014-05-28 by Phil65

Hi Bob,
You are really helpfull. Merci !

1) I did the DAC calib again and turning VR6 CCW  => from led 8 to led 7 6 then 5,  while turning VR7 CCW from led 8 to 7 then 6
2)   pin 3 of IC18 and pin 1 of  IC27, OK
3)  pin  6 of IC18 and IC23-4.  OK
4) pins 9,10 and 11 of IC18 and  19 should be connected to  each other and to IC22 ?
  It seems I have a problem here. I found only IC18-9 + IC19-9 + IC22 -5 , IC22-19 and IC22-35 connected together. Nothing between IC18-10 (IC18-11) with any pin of IC19 or IC22 ??
Shall I strap IC18-9 + 10 + 11 

5) With power on, you should be able to vary a front panel
 control,such  as filter cutoff, and see IC7 pin 7 change voltage as you
  do it (in manual   mode).

3.177V => 3.120V cut off from 10 to 0 with all controls at normal setting

  
 6) when you select different patches, you should see the  attack at IC10-1decay

=> On IC 10-1 no change always 13.56V

 7) Decay  at IC10-7 ?

=>slight variation between patches. In manual mode and normal setting with decay control from 0 to 10 => 3.240V to 3.346V


 Thanks for your help, really appreciated !
Phil

--------------------------------------------
En date de : Jeu 29.5.14, Bob Grieb bobgrieb@yahoo.com [PolySix] <PolySix@yahoogroups.com> a écrit :

 Objet: Re: [PolySix] EG and VCF not working after battery leakage
 À: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
 Date: Jeudi 29 mai 2014, 0h21
 
 
  
 
 
 
   
 
 
     
       
       
       Hi Phil,
     
 If you are seeing LEDs 1 and 8 in DAC calibration mode, that
 impliesthat
 the DAC and the input muxes are working.   Another thing
 to try - 
 in
 the DAC calibration test mode, turn the two controls that
 you were supposedto
 set for this test, and you should see the LED's
 change.
    
 Don't worry about the click noise test for
 now.
    
 The voltage demux for controlling the EG and the VCF is
 mostlyIC18
 (4051).   I would check with the ohmmeter that you have
 good connections(with
 the power off, of course) between pin 3 of IC18 and pin 1 of
 IC27, and between 
 pin
  6 of IC18 and IC23-4.  Also, pins 9,10 and 11 of IC18 and
 19 should be connectedto
 each other and to IC22.   
 
    
 With power on, you should be able to vary a front panel
 control,such
 as filter cutoff, and see IC7 pin 7 change voltage as you
  do it (in manual 
 mode).  
 And when you select different patches, you should see the
 attack at IC10-1decay
 at IC10-7, etc changing with different patches.  Be careful
 when probing with 
 the
 power on not to short anything or you can damage chips in an
 instant.  Use the gndtest
 pt for the meter black or negative lead.
 
 
    
 Tell us what you measure at these points in the circuit and
 if they vary with the 
 corresponding
 front panel control in manual mode, or when you change
 patches.
    
 Bob
 
        
 From:
 "Phil65 phil0065@yahoo.fr [PolySix]"
 <PolySix@yahoogroups.com>
  To:
 PolySix@yahoogroups.com 
  Sent: Wednesday, May
 28, 2014 6:05 PM
  Subject: Re: [PolySix]
 EG and VCF not working after battery leakage
    
 
  
 
 
 
   
 
 
     
       
       
       Thanks Bob for your quick answer !
 
 
 
 Seems that my patch looses "EG" from memory. I
 have no sound unless I put the VCA switch from EG back to
 "square" again to get some sound. 
 
 Not sure to keep the bank memory even when polysix is still
 on.
 
 
 
 I did the procedure and it passes directly. Here a quick
 summary:
 
 *dummy 56 ohm => all leds on
 
 *remove resistance => A1 leds
 
 *SW1 in test mode and tape switch to enable => Only leds
 1+8 on 
 
 * SW1 back to normal => still leds 1+8
 
 * "7 ) confirm that output DC click noise is within 6V
 p-p when power is switched off" => sorry I don't
 understand precisely what to do/ measure?
 
  * Power on again => A1 leds on.
 
  
 
 Thanks for your support 
 
 Phil
 
 
 
 --------------------------------------------
 
 En date de : Mer 28.5.14, Bob Grieb bobgrieb@yahoo.com
 [PolySix] <PolySix@yahoogroups.com> a écrit :
 
 
 
 Objet: Re: [PolySix] EG and VCF not working after battery
 leakage
 
  À: "PolySix@yahoogroups.com"
 <PolySix@yahoogroups.com>
 
  Date: Mercredi 28 mai 2014, 2h09
 
  
 
  
 
  See if
 
  these functions can be controlled correctly when using
 
  patchesin
 
  memory.  If so, then the output from the CPU to the
 analog
 
  circuitsis
 
  OK.   Then you have a problem with reading the
 
  controls.But
 
  if the sound is always the same with all programs, then
 the
 
  
 
  output
 
  circuit is bad and maybe t is reading from the pots
 
  OK.Did
 
  you try the DAC calibration test in the manual?  It
 would
 
  be helpfulto
 
  know if that is working OK.  Just the part where you try
 to
 
  get the 
 
  two
 
  LEDs to light up.
 
   
 
  Bob
 
   
 
         
 
  From:
 
  "phil0065@yahoo.fr [PolySix]"
 
  <PolySix@yahoogroups.com>
 
   To:
 
  PolySix@yahoogroups.com 
 
   Sent: Tuesday, May 27,
 
  2014 6:02 PM
 
   Subject: [PolySix] EG
 
  and VCF not
 
   working after battery leakage
 
   
 
   
 
  
 
  
 
        
 
        Bonjour !I am
 
  French
 
  and happy to join this group of Polysix owner. My old
 
  Polysix bought back in
 
  1983 has been sleeping in the attic since 1990, until I
 have
 
  returned back now to
 
  my first love. Unfortunately I have discovered the
 battery
 
  leakage problem !
 
  So I did
 
  the standard procedure (like many)Spend a
 
  lot of time checking the lines on KLM-367 with plenty of
 leds on at start
 
  up.. Browse internet for hours (discover service
 
  manual, old crown, etc)…, change IC
 
  30 & 31 … recheck continuity, still few leds
 
  on..Recheck again, change all set of
 
  panel switches (vintage planet)..4 leds on... Bank B not
 
  working...Check
 
  lines again, to get finally only leds A1
 
  on start up. Great !
 
  Unfortunately sound
 
  is not OK.
 
  Tune seems
 
  OK,
 
  6 voices are OK, voltages from power board are OK (15V,
 5V
 
  -5V and -15V) all pots
 
  and switches seem to work except the 4x EG and 4x VCF
 pots
 
  which are not
 
  active! I think at
 
  this stage it is useless to do the calibration procedure.
 Is
 
  there some indications,
 
  checking to start with to define if it is still a
 
  line/continuity problem or if electronic parts (IC,
 diode..)
 
  should be changed.
 
  Thanks in
 
  advance for your help
 
  
 
  
 
   Phil
 
  
 
  
 
       
 
 
 
     
      
 
     
     
 
 
 
 
  
   
 
     
      
 
     
     
 
 
 
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