Working BIOS for a Sony VAIO M850 series machine on board MBX-204, provided as a 2.57 MB RAR. MBX codes are Sony's own internal board identifiers for VAIO laptops. With the dump marked as working, it can be used to rescue a unit with corrupted firmware by reprogramming the SPI flash with a hardware programmer. Check that the board carries the MBX-204 marking, read and save the existing chip first, and confirm the extracted image matches the flash chip size before writing.
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.
All sources (2)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @biosarchive | 26 May 2022 | Open file on RM Schematics |
| @fileservicelaptop | 13 Jun 2022 | Open file on RM Schematics |
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 →