Lenovo firmware archive for the NM-A841 mainboard, revision 1.0, with CG521 as the project code. NM-xxxx numbering is used by LCFC, the Lenovo-owned ODM, for its laptop boards. The 2.71 MB RAR presumably contains a BIOS dump for reprogramming the SPI flash with an external programmer when the machine does not boot or the firmware is corrupted. Before writing, save a copy of the original chip, check the NM number and revision on the PCB, and confirm the image size matches the flash chip capacity.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →