Yamaha CS80

Stephen Teller wrote:
> I've got two keys on my CS-80 that are not responding to aftertouch.  
> What is the procedure to disassemble and get to the aftertouch  
> sensors and check them?
>   
Here's the quick version - see pictures in Photo/Take Apart

Remove big screws from bottom of unit so that panel hinges up.

Remove screws holding down panels to the left and right of the keyboard

Remove screws holding down rack with all the cards behind the keyboard.

Lift up card rack.

Remove screws on left and right side of keyboard plywood platform.

Slide keyboard platform back (goes about 1/2 inch).

Remove two metal bars over keys.

Remove plastic key contact cover from back of keys (snaps off).

Remove keys. Note, you have to remove black keys next to any white keys 
you want to remove. Black keys are easy - but be careful around switch 
contacts at back of key.  White keys need more careful work to get from 
lip out from under metal edge.  You'll likely have to remove a whole 
octave of keys.

Once keys are out, you can see rubber aftertouch sensors along front of 
keys.  They are in strips of 7 for white keys and 5 for black keys.  To 
take apart, remove the two screws.  The white, nylon frame will come 
off, and then the 5 (or 7) rubber pads will be loose.

However, I'd first stick a volt-meter from ground to the appropriate 
wire coming off the sensor (should be obvious which is which).  Just 
push on the rubber pad with your finger and see if the voltage goes up.  
Check a good one first for reference.

If this is good, then it's not the sensor, but something in the wiring 
or the circuit boards.  If it's not, try taking apart the sensor and 
cleaning the contacts under the rubber pad with a q-tip and alcohol.

Don't do any of this if you're not comfortable with this kind of thing.  
I provide no warranty!

Good luck!

 David