A schematic diagram for MSI hardware (board MS-7975). Shared as “MS-7975 VER 10(00017967) PDF .rar” — a .rar file, 1.19 MB.
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 @generalbios. 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.
7-ZipWinRARThe Unarchiver (macOS)