A schematic diagram for Lenovo hardware (board NM-A271). Shared as “4c2c9_NM-A271_G50-80(ԭG40-70).pdf.rar” — a .rar file, 1.22 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 @generalschematics. 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.