This comprehensive service manual provides in-depth technical information and repair procedures for Yamaha's RX-V861, HTR-6080, DSP-AX861SE, and DSP-AX861 models. It covers a wide range of topics, including detailed views of the front and rear panels, remote control panel diagrams, complete specifications, and a detailed internal view of the unit. The manual also includes step-by-step disassembly procedures, instructions for updating firmware, and a comprehensive guide to utilizing the self-diagnosis function (DIAG). This manual is an invaluable resource for qualified service personnel who require a thorough understanding of these Yamaha models for repair and maintenance purposes.