A boardview (component placement) file for Apple hardware (board 820-3115). Shared as “APPLE__A1278 __820-3115-B __BOARDVIEW_(Luirons_Esquemas).rar” — a .rar file, 121 KB.
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 @Satale_bios_esquemas_Laptop. 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.