hi
you can find an owners manual here
http://www2.yamaha.co.jp/manual/english/download2.phpno schematic tho.
the touch sensitivity is not quite a regular arrangement - you can
read up on how it works in the manual, maybe it is working but just
not what you expect.
it may not be a good idea to go poking around, power on, without the
schematic, too easy to fry things.
you could look for obvious faults (unplugged) - loose wires or broken
solder joints, burnt out components.
old analogs can get out of tune...tho 4-5octs is a worry.
hope this is a start.
andrew
--- In oldsynths@yahoogroups.com, "zendenker" <doof@c...> wrote:
> Hi all,
>
> Please keep in mind I'm new to troubleshooting and repairing vintage
> synths, also I have posted a similar msg to other groups, so I
> apologize for any repetition..
>
> I recently acquired a CS-50. I really love the unique sound of this
> synth and can't wait to record it. It has 2 problems though: the
> touch-sensitivity is not working and one of the voice cards tracks
> the keyboard, but with a pitch about 4 or 5 octaves above the other
> voices-- this voice squeaks instead of squaking.
>
> Since I have 3 perfectly fine voice cards, I figure I can use one of
> those to pinpoint the problem in the faulty card. I'm armed with a
> radioshack volt-meter, but I'm not sure where to go from here.
> Would the best method be to measure voltage between components and
> do a one to one comparison? Say, if the voltage differs in the same
> point on both cards, I would know the problem is in that area and I
> could simply replace that component? Does this sound like the right
> strategy? Unfortunately I don't have any schematics, and only a
> partial service manual for the cs-80 is on the web (nothing on the
> voice boards). I'd appreciate any tips/suggestions. Thanks.