[sdiy] Polysix w/korg midi retrofit. Anyone ever work on one/know where to get schemos?

[Bob Weigel]

PS I forgot to say I noticed the power supply had crept up in 5V and I 
couldn't get it below 5.8V or so now so I decided I'd best look into 
that.  It had a 1 ohm jumped onto the 1ohm R3.  Pulled it and now it 
won't adjust at all. uh boy...4.2V  I imagine this was a mod that went 
with the retro.  The 5V regulator transistor has a wire that goes over 
to a board by the xformer that has another xformer on it and a few fuses 
and an electrolytic. -Bob
Bob Weigel wrote:

> My polysix synth board schemos really aren't very good anyway.  But I 
> thought this thing was going to be a relatively easy fix.  I got the 
> battery spill repaired.
>
> Then...it worked save a few LED's on that shouldn't be (C and 3) and 
> the pitch/mod didn't work.  When I wiggled the main cpu i/c to the 
> retro board, I would get pitch jumping around then in the right 
> position the wheel and pitch worked as well as the tune knob.  I 
> pulled the i/c and looked and sure enough it was parting and some 
> obvious bad connections.
>
> I did a bang up job hard wiring it.  My reward?  Tunings are totally 
> goofy.  All over the map.  Wiggling things around it seemed the early 
> production sub board i/c might be the problem though..I was having a 
> hard time seeing how that would make this problem...but now I was 
> actually able to get the synth to play in tune with nice timbre's and 
> noticed that the LED's were no longer on that shouldn't be....but the 
> pitch and wheel wouldn't work at all now!
>
> In the process I got a strong correlation to the other cpu i/c and 
> soldered it too.  OH and I should mention that the tuning...was 
> floating.  I could touch the op amp and shift the tuning 
> baseline...widely.  and it would stay there up above!  Weird huh?
> Anyway now after resoldering the second cpu it just went totally 
> worse.  Haven't gotten more the tic tic lf sounds out of it. -Bob
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