finally I fixed the problem of bass section not
working replacing the LM709/14 pins op amp with a new LM741/8 pins: now
everything in my old Solina works well !!!
But now that I know well the schematics of the
keyboard I would want to make a maintenance in order to bring back the sound as
good as possible. Which parts (capacitors, etc) have I to replace in order to
renew the sound and the chorus ? I mean which parts influence the quality of the
sound ?