Firmware package for a Lenovo laptop built on the NM-C791 main board, a number that follows the LCFC numbering used by Lenovo's own ODM. The name only says main, so expect the main BIOS image rather than a separate EC dump, though the 11.4 MB ZIP should be opened to confirm what is inside. Technicians write such images to the SPI flash with a programmer like the CH341A when a board will not POST or the BIOS is corrupted. Read and save the original chip contents first, and check that the image size matches the 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 @efibios. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →