Rhodes Chroma Polaris

i just got another polaris off ebay---it supposedly had only  a keyboard contact problem which i was going to fix...but apparently now that it arrived most of the controls are dead--- the LEDs go on but all the sliders  dont have any effect...ALL sliders from volume to assignable. even the benders.  I can change through all the programs (letters /numbers)  and it seemed to go through  auto tune- [6 blinks] ... but i cant modify the sounds. IT SEEMS THAT  ONLY 3 BUTTONS DO WORK... noise, sine-square , and touch on/off for volume. 
 there had been a ribbin wire repair from left to right board on the lower connector ( using spliced in wire). but not the upper smaller ribbon.
i have tested for a simple continuity accross the repaired ribbon between the left and right board and it seems to be ok. any ideas which ribbon (i assume a ribbon wire)  would be at fault to affect this odd array of controls.  i have the service manual and schematics, but they dont show this type of info clearly to me (perhaps its in there somewhere?)