Yamaha CS80

Hello everyone!

I have a problem with the Yamaha CS70M, it's the pitch bend on the 
last 6 highest notes G - C6, they wount go up a hole octave instead 
stops at G6 on all last 6 keys.

All ref.voltages from the service manual are correct (from keyboard, 
to the 12 voice cards), and when pitch bending a hole octave the key 
voltage doubles, for the highest key you have 4volt CV in on leg2 
(key voltage input) IG00153 and when pitch bend full upp: 8volt, but 
when the CV reaches 5.7volt the pitchbend stops. 

This is for all voice cards there is 12 of them, and i cant belive 
that all VCO IC's are faulty. Can it be a design fault from Yamaha?

How is it with the CS-80? when pitchbend fully up, have anyone 
measured the CV voltage on the IG00153 IC?

Would be greatful for all help!

/Anders