This comprehensive service repair manual for the Sony STR-DE405 and STR-DE505 audio receivers provides detailed information and instructions for technicians and repair personnel. The manual includes a vast array of technical specifications, circuit diagrams, troubleshooting guides, component identification, and step-by-step repair procedures. It covers all aspects of the receivers, from the power supply and amplifier sections to the audio processing and input/output circuits. This crucial resource empowers technicians to diagnose and repair common and complex issues, ensuring the receivers function flawlessly. Whether you're a seasoned professional or a dedicated hobbyist, this service repair manual is an indispensable tool for maintaining and restoring Sony STR-DE405 and STR-DE505 audio receivers to optimal performance.