sci sixtrack - HELP!!

[geoffery francis james]

I've been endeavouring to repair the above machine for a local muso and
have reached a dead end.

Having cleaned all switch contacts and tuned the dac all functions appear
to operatae ok, but the  top two octaves are right out of wack on all
voices.

I have done the software reset, but this did not fix the problem.

Can anyone please shed some light on possible causes.

Thanks in advance.

Regards,

Geoff James