Sony schematic identified only by GD1B, which follows the Quanta project-code style, GD1 with a B suffix, though no MBX board number or model is given. Because the name is sparse, open the 734 KB PDF and check the title block for the board number and revision, then compare with the code printed on your PCB. Once matched, the drawing helps trace power rails, locate components and test points, and follow signal paths when diagnosing a VAIO that will not power on.
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 @schematicslaptop. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.