A schematic diagram for MSI hardware (board MS-16J21, MS-16J2). Shared as “MSI MS-16J21 MS-16J2_1792 Rev 0A PDF(PK).pdf” — a .pdf file, 3.00 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 @pkbiosbdv. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.