Problem solved. IC30 has been replaced as well (leftmost on board).
BTW, before replacing it I noticed that the leds which where on,
were the Write and bank 6. If you check the schematics, you'll find
that they both connect through the same rail to IC31's leg number 6.
(pin 11 of connector CN10, "D06" rail on KLM367 schematics). Very
small degree of corrosion and acid was found under this IC as well.
Cheers !
--- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> I have a nice looking P6 here. Battery has leaked and severely damaged
> the 74L08 near it and all traces beneath. The symptoms where
> non-functioning Release and VCO '16 Oct functions, and cases where a
> few preset leds light up together including the Write button led which
> will sometimes light on and will not turn off. Also, pitch and cutoff
> can change spontaneously as you play some chords.
>
> I had it retraced and cleaned of course, and replaced the 74LS08 and
> 4011 above the battery (although the latter looked ok).
>
> The current situation is that the Release and VCO '16 Oct functions
> work ok, but the mess with the bank preset leds still exists. Can you
> spot a particular IC which can cause the problem ? Other ideas ?
>