Lenovo NM-A221 schematic, provided as a PDF compressed into a 1.51 MB ZIP file. The NM-prefix board number belongs to LCFC, the Lenovo-owned company that designs and builds many of its laptop mainboards. Technicians rely on such schematics to identify power rails, check the power-up sequence, read signal names between chips and find replacement values for burned parts. The name does not include a revision, so compare the PCB marking with the schematic title block before using it for repair decisions.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.