[sdiy] juno 106 (illogical) behaviour

[Antonio Tuzzi]

so...
was not a cpu fault but the keyboard pcb with interrupted traces
(you all were right!)

http://img46.imageshack.us/img46/6109/img1560el.jpg
http://img33.imageshack.us/img33/1269/img1562xn.jpg

but WHY?!

corrosion ? is in 6 different spots
drag from keys ? (a couple of spot presents kind of scratches) (but keys don't touch the pcb!)

I'm quite sure nobody opened the keyboard before

for the 2 button in the front panel, are simply failing switches

Thank you
Antonio
 

On 22/feb/2012, at 12.28, Antonio Tuzzi wrote:

> 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)
> 
>