Yamaha CS80

I think that I might have the same problem.  My keybed acts funny from the top key down to the C#.  It will trigger, somewhat strange noises, if I have another key pressed in a lower octave.  Is this the same problem?  How did you troubleshoot it and fix it?

-Mike

--- In yamahacs80@yahoogroups.com, "tmoravan" <moravanskyt@...> wrote:
>
> I originally reported a problem w. my CS80 in that the top octave of keys wasn't triggering any sound.  I had some good suggestions from various techs and I verified that the actual keybed was sending the correct voltages from all keys.
> 
> The testing and debugging centered around the KAS board.  After carefully measuring the values for various keypresses up and down the keyboard, I came to the conclusion that the YM26600 was creating and assigning the right codes, but the YM26700 IC was not working properly.
> 
> Thanks to the kindness of a listmember, I popped in a replacement YM26700 and now I have the full range of keys again.
>