Yamaha KHY-M4570-015 I/O Head Board for YS12/YG12/YS100/YS88/MC-12 The Yamaha KHY-M4570-015 I/O Head Board is an electronic control board used in compatible SMT pick and place equipment. According to the supplied hardware manual, the KHY-M4570-0XX I/O HEAD BOARD ASSY family is designed to connect up to six KHN-M5802-XXX Servo Unit Assemblies . It supplies several DC voltage levels required by the control system and relays communication, digital input and digital output