RAR archive labelled ASUS X551CA containing BIOS firmware for that notebook, with no board revision or version indicated in the name. It is 3.56 MB compressed. Unpack it and check whether the contents are a full SPI dump or an update capsule, then compare the image size with the chip on the board. Technicians use such files to recover boards with corrupted firmware via a CH341A or similar programmer. Check the PCB revision first, and back up the original chip before erasing it.
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 →