Casio CZ/ VZ/ FZ - Pro Series

My CZ-1 is sick.  I turned it on for the first time in a long time
and it would appear to have some problem in the output cicuitry.
If I play sustained notes (organ, for example) the sound will come up 
to volume and remain played.  Sounds with a fast attack and decay
hardly sound at all.  There is some noise (static) as well.  Anyone
else experience this?  Anyone know of a fix?  I'd hate to have to 
dump my first real keyboard after all these years... (bought it in
82/82 or so for 800!!!  (My first electonic keyboard was the VL-Tone,
anyone remember the 'German Folk Tune'?)  Thanks.

                                                 ---john