ASUS X421JA BIOS dump for board revision R2.0, sized for a 16 MB flash chip and marked OK, meaning it was reported as working. It ships in a RAR archive of roughly 6.12 MB. Flash it to the SPI chip with an external programmer to revive a laptop with corrupted firmware. First confirm the motherboard reads X421JA R2.0, read and save the original chip in case serial or activation data must be restored, and make sure the extracted image is exactly 16 MB to match the chip.
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 →