This seems to be a common problem, and should be addressed by Casio.
I have the same - won't turn on but there is power through the cord to the machine.
One day it just decided not to turn on.
Will Casio talk to anyone? Probably a simple fix - unless the mother board is fried.
Someone asked whether there is a fuse within the piano, but I have not seen an answer.
CASIO - if you are out there, talk to us!