RAR archive for the Lenovo Y520 built on LCFC board NM-B191, the numbering format of the ODM that manufactures many Lenovo laptops. The name does not list the contents, so expect a schematic and possibly boardview or BIOS files, but check after extracting with WinRAR or 7-Zip. Such material is used to trace power rails, locate components and test points, and fix no-power or short faults. Confirm the NM-B191 code on the PCB matches, and back up any original chip before flashing a dump.
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 @ITHINKHS. 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.