ZIP of 4.76 MB for a Sony VAIO motherboard MBX-266, following Sony's own MBX board numbering. The file name does not say whether the archive holds a schematic, boardview or firmware, so open it to confirm. Material for MBX boards is commonly used to trace power rails, identify components around the charging and power circuits, and diagnose no-power or no-display faults. Check the MBX-266 label and any revision marked on the PCB, since Sony reused model names across different board versions.
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 @ITHINKHS. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.