EC firmware for the ASUS X555LD, board revision 3.3, intended for the IT8585 embedded controller from ITE, as named in the file. The archive is only 29.6 KB, which matches a small controller image rather than a full BIOS. A failed EC can cause no power, no charging or keyboard faults, and reflashing it is a common fix. Use a programmer or tool that supports the IT8585, back up the existing firmware if it can be read, and confirm the board revision 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 →