Archive of the former Yahoo!Groups mailing list: Yamaha CS80

Hi all,
I desparately need some help. I dug out my CS50 again today and made another atempt to figure out what's wrong with it. Basically, I have one voice that won't tune. The notes are always too flat compared to the other notes l. There is no possible way to get the note in tune even if I lower the other voices.

The second issue, is that I have one other voice that has a stuck tone and it sometimes slowly dies off to a lower tone over time.

NOW, here's what I did today. I measured the voltages K1-K4 on the SH board and the voltwge on the K terminal for the voice that is slightly out of tune I cannot turn the trimmers on that voice or the other two good voices so that they are all a value close to each other.
The K terminal for the stuck (or whatever) voice has a way lower voltage on it.

I am not sure if these voltages are coming or going frok the SH board. What direction does this lead me in? Do I inspect the SH board or follow the path of the bad voltages somewhere else.

Sorry if this is a somewhat dumb question. There are parts of the CS50 block diagram that confuse me.

Please help me out if you have any ideas. I desparately want to play this thing now. Right now I have to resort to muting the two weird voices and playing only two keys.


But then after fixing this, I am still not done. The portament glisando doesn't seem to work but it works sometimes no matter what on one voice.