[sdiy] bit one

[Rude 66]

with all this talk of faulty mks70's, i'm having a bit of a similar problem
with my crumar bit 01, that's the rack version with 'proper' midi. the
problem is that it sounds corrupted.. all sounds are out of tune, the bare
vco's sound terrible, on patches with an open filter  it sounds like the
gate stays open after the env release closes, there's a continuous noise but
on a lower lever as the patch itself.
all functions work: oscillator, lfo's, eg's and vcf are all there, as is
polyphony and midi. it started doing this one day, and i changed the
internal battery first, but to no avail. if i send it factory patches via
midi or tape (!!) they arrive corrupted, and it just always sounds sick. so
it probably has nothing to do with a power-up spike voltage.
what could be going on here? i'd like to troubleshoot it as good as possible
first before i let someone look at it..all parameters are there and respond,
just not like they're supposed to. it almost sounds exactly like what i had
on my earlier bit one keyboard version. the bit is a 6-voice mid 80's
italian polysynth, only known thing inside is 6 cem3328 vcf's.  could it be
a problem with a memory chip? the connector from the front panel to the
board? i've pushed all chips in gently, and dis- and reconnected the various
connectors. the synth never moves around much either. any leads or tips
would be appreciated..

thanks!

ruud