Xpantastic!

hello all, thanks so much for your help. so i disconnected the rear harness of the TOP voice board that connects to the main processor board, and the machine boots. it reads:

"voice 1 processor malfunction"

and then enters the main screen. all buttons/pots work, and i am able to select programs. however, i get no sound.

if i enter the tuning page, i get this error"

"voice 0 processor malfunction"

so i've narrowed it down to a problem in the top-most voice board, i believe. now what do i do? any ideas on how to deduce the problem on that board? thanks, rj