Lenovo archive for board NM-C661, revision 1.0, an LCFC-numbered design from Lenovo's own ODM. No laptop model is named, and the 28.6 MB RAR may bundle a schematic, boardview or firmware, so check its contents after extracting. These files help trace power rails, inspect the power-on sequence, locate components and probe test points on the board. Before trusting them, confirm the NM number and revision printed on the PCB match this file.
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 @ShareMan_Electronic_Files. 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.
7-ZipWinRARThe Unarchiver (macOS)