Sony motherboard BIOS firmware archive for the board numbered MBX-240, packed as a RAR of about 2.78 MB. Sony uses the MBX prefix for VAIO laptop mainboards, so the number should be printed on the PCB itself. The name says nothing about chip type, version or test status, so open the archive and check what images are inside before use. A technician would flash such a dump to the SPI chip with a programmer such as a CH341A, after first reading and saving the original chip and confirming the image size matches the flash capacity.
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 →