This comprehensive service manual provides a detailed guide for servicing Yamaha RX-Z1 and DSP-AZ1 AV Receivers and AV Amplifiers. The manual covers a wide range of topics, including the impedance selector, front and rear panels, remote control functionality, and detailed specifications. It also includes internal views, step-by-step disassembly procedures, and a thorough explanation of the self-diagnosis function. For advanced troubleshooting, the manual offers guidance on amp adjustment, display data analysis, and IC data interpretation. Additional resources include a block diagram, printed circuit board layout, pin connection diagrams, schematic diagrams, and a comprehensive parts list. This manual is an essential resource for service technicians seeking to understand and repair these complex audio components.