This comprehensive service manual provides detailed technical information for the Yamaha RX-V863, HTR-6180, DSP-AX863SE, and DSP-AX863 audio/video receivers. It includes detailed instructions for service personnel, covering a wide range of topics, including front panel and rear panel components, remote control panel operation, comprehensive specifications, internal component layouts, step-by-step disassembly procedures, firmware update instructions, and a comprehensive self-diagnosis function guide. This manual serves as an essential resource for qualified technicians who need to diagnose, repair, and maintain these Yamaha audio/video receivers.