Discussion about the Korg PolySix synthesizer

Hi,

Check the line "P24" from the patch CPU (pin35 of IC22 on KLM-367). It
is the clock line for the latches for these signals (Octave, etc.)

"crashes sometimes": perform the "Reset Circuit Adjustment" as given
in the service manual. Check the TAPE ENABLE switch and its line to
the programmer CPU (pin  6 of IC22).

General: check all the lines from programmer CPU (IC22) to IC30/31
(data bus buffers), IC26/24 (adress latches, IC24 is errornously
labeled "IC34" in the schematic), IC32 (RAM), IC28/29 (digital control
latches), IC34/35 (digital control latches), and IC18/19 (analog
demultiplexers). From experience IC31 and IC30 are often affected
from battery acid eat-up, as they are located close to the battery.

Do all checks using an Ohmmeter.

Be patient and insistent - you will fix it and it is worth!

Good luck!

Johannes


analogfuture wrote:

>  Hello,
> 
>  I have spent the better part of the day sifting through old posts to 
> this forum, which proved very useful... I suffer from a certain 
> degree of phobia and ignorance when it comes to digital circuitry, 
> but it looks like I have no choice but to befriend the KLM-367 
> somehow, since most everything important goes through there. My first 
> analog synth, and the major problem is positively in the digital 
> section of it...somehow that doesn't surprise me. Anyway...
> 
>  A number of people describe problems that (from my memory) I have 
> with my Polysix:
> 
> -Octave selector not working
> -Waveform selector not working
> -Sub osc. selector not working
> -MG "MOD" selector consistently modulates VCO pitch regardless of   
> setting
> -General patch memory problems 
> 
>  In addition, mine some times will "crash", and messing with the 
> tape enable/write enable selectors brings it back to life.  
> 
>  It seems common for these malfuctions to be part of the problem of 
> a failing KLM-367. Even so, major parts of the analog synth 
> (virtually all pots) work okay, so the damage is likely to be 
> somewhat limited, at least confined to the 367 board.
> 
>  Clearly the stock battery in my P6 was replaced before the board
> suffered serious damage, so I have some hope of being able to sort 
> this out.
> 
>  It's going to be a few days before I get an opportunity to get back 
> to my shop to work on the machine, so I'll stay tuned here for 
> further input and go on reading old posts to prepare me for the 
> upcoming job.
> 
> Regards to all, from
> 
> Thomas/analogfuture
> 
> 
> 
>    
> 
> 
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