【About the Product】 This is a Sony multi-channel AV receiver, model "STR-DN850." It was carefully stored in a barn in its unopened state (as shown in photo 10) after being returned from manufacturer repair. It was opened for the first time for photography and power-on confirmation for this listing. ■ Key Points of This Product (Major Parts Replaced) In the past, the main board, power transistors, fuses, and other core components were completely replaced during manufacturer repair. As proof of the repair, the "set of old parts" returned to me is also in my possession. Because the major electronic components are new, the internal condition is very good. ■ Results of Operation Confirmation (Reason for Being a "Defective Item") Power-on confirmation was performed for this listing. Power Operation: It can be turned ON/OFF normally using the power button on the main unit and the remote control. Relay Sound: Confirmed that the normal "click" sound is heard internally when the power is turned on. Lamps: The front lamp changes from red (standby) to green (operation) according to the operation. Display: No characters are displayed at this time. The lamp turns green, but the panel is completely dark. Sound Output: Not confirmed due to the lack of a connection environment (speakers, etc.). ■ Accessories Main unit (unused after repair/refresh) Original remote control (response confirmed) AM loop antenna Set of old parts/boards replaced by the manufacturer (see shipping below) Original box (with some damage due to storage) ■ About Shipping and Inclusion of Old Parts Due to the size of the original box, the replaced old parts (old boards, etc.) will be packed separately and securely attached to the outside of the original box for overall protection during shipping. *If you do not need the old parts to be included, please let me know via message after purchase. In that case, only the main unit (original box) will be shipped. ■ Please Note Although this unit has been repaired, it is a "defective item" due to the display not working after long-term storage. I hope it will be useful for those who can perform maintenance themselves or are looking for good condition replacement parts. Due to being precision equipment, it is sold as-is and cannot be returned.