A 15.9 MB RAR archive for the LCFC NM-C631 board, revision 1.0, used on Lenovo machines with the GL4A0 and GL5A0 board codes. The name does not list the contents, but at this size it likely bundles a schematic, a boardview or firmware, so inspect it after extraction. Such files help a technician trace power rails and signals, locate components and recover a dead board. The NM- prefix is the LCFC numbering pattern; make sure the PCB silkscreen shows NM-C631 rev 1.0.
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 @schematiclaptopramkushwaha. 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.