Sony documentation for model M750 with motherboard MBX-190, packaged as a 900 KB RAR. The name does not give a revision, so check the PCB for a revision marking and compare it against the drawing title block. VAIO motherboards carry the MBX-xxx number printed near the board edge or under components, and it is the most reliable way to pick the correct file. The schematic inside serves for tracing power rails, locating fuses and regulators and finding test points when a board shows no power or no image.
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 @generalschematics. 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.