Come to the end of the road on this. For spares purchase on ebay I
suppose is the only chance. Main board problem , cracked die of a 100
pin Roland chip it seems.
Common rail to this IC11 for the missing bank of keys is pin92. pin 90
is the common for the next bank of keys 33 to 40, which do sound.
DVM-D and R checks on those 2 pins to 0 and 3.3V rail match as does
powering up and both commons drop from 3.3V to 2.9v on a relevant key push.
Any other ideas to persue?