jeffshercaseyvi@yahoo.com.... Hey.... Jeff here. Small brass, woodwind and guitar shop in Paradise. I have a DOA Casio WK-6600 from an elderly lady. I said I would have a look. Meter says 12.3V DC on the business end... kb does not want to fire up... display is blank. Is there an internal fuse? Always happy to learn something new. thx...JB