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

From: Phil65 <phil0065@yahoo.fr>
Date: 2014-06-24


Hi,
It has been some time since my last email and I would like to update on my P6 issue with no sound except in EG square position. 
Eventually Bob were right, IC10 and IC11 were dead. Changing  both of them solved by initial problems (even bank c and 3 issue have been cleared). 

Now my remaining problem is a noise problem when playing the polysix (not always but sometimes). I believe this can be described more as a scratchy sound problem, like a faulty pot, cap, transistor or line. 
Is there a way to directly spot the origin of problem? I have started the calibration procedure and completed the KLM367 checking without problem?

Thanks for your advice!
Merci
Phil



De : "Bob Grieb bobgrieb@yahoo.com [PolySix]" <PolySix@yahoogroups.com>
À : "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Envoyé le : Jeudi 5 juin 2014 0h53
Objet : Re: SV: [PolySix] EG and VCF not working after battery leakage

 
I am starting to think that trying to troubleshoot over email without a scope is
not such a good idea.   If having LED 3 on affects "C" LED, this implies
an issue with the enables to IC4,5 and IC2,3.   So now I would check resistance
to IC3-6 and 7 on KLM-371 to same signals on KLM367.  P26 and P27.

IC10 and IC11 pin 1 should be the same voltage as pin 3 on each chip.
If not, then either the op amp is bad, or something is shorting the output
to this voltage.  Maybe unplug CN05 on KLM-367 which is the only
place these signals go.  If the voltages are still so high, then replace the
op amps.  

The IC18 circuit is a sample and hold one.   The DAC connects to each of
the caps in turn, through the mux (IC18) to refresh the voltage on the cap.
But the cap voltage should be limited to +/- 5V, and you should have the
same voltage after the op amp.

   Bob

From: "Phil65 phil0065@yahoo.fr [PolySix]" <PolySix@yahoogroups.com>
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Wednesday, June 4, 2014 6:14 PM
Subject: Re: SV: [PolySix] EG and VCF not working after battery leakage

 
Bonjour les amis Polysix,

1) Concerning the problem with led C+3, I have rechecked continuity between IC without success (cold and warm check). Precisely I have checked between IC31-8 and all the follwoing:
 Board 367 (Ic33-10 ic26-4 ic28-14 cn6-5 cn10-2)
 Board 371 (ic2-6 ic4-6)
 Board 370 (sw2-0)

All continuity seem OK. 
Anyway problem with C3 is not clear. It could appear after 30s warm up  or never (If I do nothing ?), unless I switch apparently effect mode buttom or led 3. It disappears if I select "manual" ... Then selecting "1" again make C3 disappear until I select "3" and then "C" light up directly ...?
 
2) For the "high" voltage please find an update of the reading (done at normal setting as shown in service manual, figure1 and manual switch on):

IC10-1   13,46
IC10-2   13,46
IC10-3   NOT STABLE  ~0,2?
IC10-4   -14,99
IC10-5   3,173
IC10-6   3,206
IC10-7   3,206
IC10-8   14,94
  
IC11 is too high too?               
IC11-1   14,2
IC11-2   14,2
IC11-3   NOT STABLE ~0,38
IC11-4   -14,99
IC11-5   3,174
IC11-6   ~3,2
IC11-7   ~3,2
IC11-8   14,94
 
SO I have checked the following (in case...):        
IC16-1   3,18
IC7-1     3,212
IC7-7     3,16
IC9-1     3,18
IC12-7   2,2
IC12-1   2,21
IC13-1   2,21
IC13-7   2,22
IC14-7   2,22

3) For the usb -scope I have try to join as an example a screen copy of the signal found at TP5 equivalent to figure 2 
"observe connector CN3-5 on oscilloscope"

 
Thanks again for your support and comments
Phil

Le Mercredi 4 juin 2014 4h32, "Bob Grieb bobgrieb@yahoo.com [PolySix]" <PolySix@yahoogroups.com> a écrit :


 
 Phil,
 
   You said you have 13.56 volts on IC10-1.   This is very strange.
Please check to see if pins 1 and 2 of this chip are connected as they
should be.   Do you see the same voltage on pin 2?    Also, measure the
voltage on pin 3.  With the output connected to the inverting input,
this op amp is a voltage follower.   The output should match the input
(at pin 3)  Pin 3 should never go beyond +/- 5 volts, since it is fed
from IC18 which has those as its power rails.   So something odd is happening
here.  Or maybe that op amp is just toast.  It seems like the output is
just sitting at its positive output limit.
 
    Bob

From: "Phil65 phil0065@yahoo.fr [PolySix]" <PolySix@yahoogroups.com>
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Tuesday, June 3, 2014 5:16 PM
Subject: Re: SV: [PolySix] EG and VCF not working after battery leakage


 
Hi
My KLM 367 repairing may not be good enough as I realize on Sunday that after 5-10 minutes of warming I have additional leds along with A+1 (led 3 then C+3 are also flashing). Disappointing..

I spend many time rechecking the board without success. After some cool down, when I switch ON, only leds A1 are on but after some timeof warming  C + 3 are coming back plus a noisy sound. 

Please find also an update on the voltage:

Does IC10 have -15 on pin 4?   => -15V

Does IC18 have +5 on pin 16  and -5 on pin 7? => Yes  +5V and -5V

I have also recheck the DAC calib. 
Cut off set to 10 => led 1+8

Cut Off from 0-8 => led 1+5
 Speed intensity 0-6 => led 1+8
Speed intensity 7-10 => led 4+8
  
Today unfortunately I do not have access to a proper oscillo. I will check what I can do with this simple USB oscillo, but I did try already and manage to get for example the correct shape for the figure 2 in the adjustment procedure (20 msec). I will send a screen copy in a next mail
Thanks
Phil

Le Mardi 3 juin 2014 14h03, "'Hans' hr.public@lonningdal.net [PolySix]" <PolySix@yahoogroups.com> a écrit :