Discussion about the Korg PolySix synthesizer

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 ?