Yamaha CS80

Hi Fernando,

It is likely to be the TSB boards. When you press a key the signal  
from the FSR on the key is buffered by the TSB circuit. I'd say that  
some of the 4051 on TSB boards are not working properly and not  
outputting the signal to the multiplexing circuits on the TKC.

It would be wise to completely overhaul the TSB boards, replacing all  
capacitors and CMOS with newer ones. I use Panasonic FC electrolytics,  
WIMA polypropylene and TI CMOS with Mil-Max gold sockets. If you need  
the digikey PN#s send me an email and i'll mail you a spreadsheet.

AK
On 01/04/2011, at 8:31 AM, Fernando Zarone wrote:

> Hello,
> my CS-80 has the following defect:
> the notes C# D D# and G G# A do not respond to AT, in all of the  
> octaves. All the others do.
> Thinking this to be a problem of TKC, I replaced all of the  
> (socketed) ICs, resoldered all of the wires, but nothing.
> The problem is shown in both CH I and II presets.
>
> Could somebody help me, please? Does the AT of these two groups of  
> adjacent keys correspond to specific component(s) / boards?
>
> I did not check the TSBs. Could they be involved?
>
> Every help is very welcome.
>
> Ciao a tutti
>
> Fernando
>
> [Non-text portions of this message have been removed]
>
>
> 

Andrew Kirkby
(e) kirkbyte@...
(m) 0416 000 070






[Non-text portions of this message have been removed]