Looks like another victim of lead-free solder in the power handling areas.

Reason for posting - idle curiosity. I'm not going to unnecessarily delve
into the keyboard section to find out.
I was surprised to see just an 8 way ribbon cable going to an 88 key, 7+
octave keyboard.
I assume there is active multiplexing hidden in there , but would there be
"touchy-feely" action monitoring as well.?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/