Service woes - Siel dk600

[Greg Montalbano]

Well, I've about had it;  been building & servicing synth devices since
about 1980, and I've NEVER had as much grief as I've had from this
@*&#%$&^%$ dk600 -- I'm just about THIS CLOSE to giving up & using the
thing for a boat anchor.

(or, more realistically, taking the voice board & creating my own synth
from that)

Before I do, has anyone out there had experience with these?  The ORIGINAL
problem was with reading the control board pots & switches -- random data.
After replacing a leaking backup battery, repairing destroyed board traces,
replacing affected ICs, and testing the ADC/DAC circuit and all
connections, the problem remained.  I've swapped boards, swapped ROMs,
tested the DIP connectors, and STILL the problem remains.
Anyone had experience with this?

Thanks.