BIOS image for the Sony VAIO PCG-61B11W on Sony board MBX-253, which the file name marks as OK, meaning a working dump. Sony's MBX numbers identify the mainboard design, so the code silkscreened on your PCB should match before you program anything. The usual procedure is to desolder or clip onto the SPI flash, save the factory content, then write this image with a programmer such as a CH341A or RT809H. Verify after writing, and make sure the file 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 @afsbiosfree. 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 →