Yamaha CS80

OK - time to yell for help.

Cleaning up a CS-80, and there's no voices sounding when playing a key.  Started debugging at the KAS.  All power looks good, note values are registering.  Nothing appearing on the trigger outputs.  Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.

Is this a dead YM26600, or is there something else causing this?

While I'm here, what should the clock input on pin 2 really look like?  I'm not really seeing a stable square wave kind of oscillation there.

thanks