[sdiy] juno 106 (illogical) behaviour

[Antonio Tuzzi]

Hello friends,

I received a defective juno
with the standard defects to some of the 80017a

but there is more: all the panel controls are working 

all the buttons are working but:
key 2 for the bank number and 4 for the patch number  are not working

the keyboard is most defective part. 
non working:
12 keys octave 1
12 keys octave 2
10 keys octave 3
7 keys octave 4
3 keys octave 5
0 keys octave 6  (is only the final C)

I cannot find any "binary rule" (reading the schematics) that brings this defect

Do I have to blame immediatly the CPU?
both keys and buttons are connected the IC 7 8 and 9
and the PB bus of the cpu

thanks 
Antonio


PS
(the synth is working using MIDI in)