On the upper control board to the left of the voice
cards, pull all of the following TL084 chips that are socketed, carefully
clean the pins with a pencil eraser and reinstall. I like to use the big artgum erasers you get at a craft store or
artists supply store, but if you have a nice, new pencil with a soft eraser,
that will work too.
On the upper right quadrant:
137
138
139
140
Middle right:
146
147
That should do it. If not, let me
know.
Scott in Ohio