Discussion about the Korg PolySix synthesizer

Hi Robert,

Are you repairing a board that has been acid damaged? That is an awful lot
of silicon to be changing in one go! If you can¹t set up the reset circuit
properly and just get a permanent active low in test mode then try replacing
zener diode D2. As far the switches being in trouble do check the operation
of the quad latches IC28/29/34/35. Moreover make sure there is a pulse train
at the clock pin (5). If this board has had an acid spill then the lines
back to P24/25 on the CPU are prone to becoming disconnected as they run
under where the battery used to be!

Cheers,
Andy  




On 23/02/2011 17:57, "robobob66" <robertleiner@gmail.com> wrote:

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> Hello list.
> 
> I'm working on a broken KLM367 where i so far have put new logic
> on IC 30, 31, 24, 26, 28, 29, 34, 35.
> 
> When i test the reset circuit with a 56kohm dummy all the leds light up but
> won't change when i adjust VR1. It only changes when i remove the dummy and
> adjust on VR1.?
> 
> The polysix makes sound and all pots works except all the switches on KLM 369
> dont work. The sound it self sounds like its being modulated by an fast lfo
> that wont go away and it's not from the polysix lfo! bad A/D?.
> 
> Ok, any light on this matter is help full!
> 
> /Robert Leiner
> 
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