Casio MZ-X300 and MZ-X500 Group | So, I've been looking for a service manual for the MZ-X500 with no luck, so I've started to take it apart without one
Casio MZ-X Series (MZ-X500 & MZ-X300): Arranger Keyboards for the serious musicians - KeytarHQ: Music Gear Reviews
CASIO MZ-X500 Service Manual download, schematics, eeprom, repair info for electronics experts