Lenovo BIOS archive for an LCFC motherboard NM-C433, with the ISC tag in the name and marked OK, which suggests the dump was tested as working. LCFC is Lenovo's own design unit and uses the NM-xxxx numbering on its boards. The image goes back onto the SPI flash with a hardware programmer when the laptop powers on with no display or loops at boot. Back up the current chip contents before erasing, compare the file size with the chip capacity, and confirm the NM-C433 marking on the PCB.
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 →