ASUS X551CA BIOS firmware tied to the SX029H configuration, stored as a 3.60 MB RAR archive. A dump like this is used to recover a laptop that will not POST because of corrupted firmware, by writing it to the SPI flash chip with an external programmer such as a CH341A. Read and save the existing chip contents first, since they hold the serial, MAC and other unit-specific data. Also make sure the image size equals the chip capacity, or the write will fail.
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 →