Sony MBX-237 motherboard schematic in PDF form, about 2.7 MB. The file name gives only the board code, with no revision, ODM or laptop model stated, so the exact VAIO series should be confirmed from the board itself. A schematic like this shows the power sequencing, voltage regulators, clock and reset circuits and connector pinouts, which helps when measuring rails or hunting a shorted component. Any PDF reader opens it; check the MBX number and revision silkscreened on the PCB before following it.
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 @notebookschematic. 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.