Quanta BL6 board package, a 5.05 MB RAR archive whose name gives only the project code. No revision or board number is listed, and the content type is unspecified, although the size suggests a full schematic set, possibly with boardview data. Use it to trace rails, identify parts by reference designator and work through no-power or no-display faults. Before relying on it, match the DA0-prefixed code and revision printed on your motherboard against the documents inside.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.