PDF schematic, 1.02 MB, whose name points to the Sony VAIO board MBX-247; the trailing hk1 token is not explained by the name and may denote a variant or build. Confirm both the board number and revision in the title block on the first page. A technician uses such a diagram to trace the power sequencing, charger and CPU supply rails and to find test points around a failing circuit. Compare the MBX number silkscreened on the PCB with the document before working from it, as variants can differ.
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 @cyberlanelectonik. 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.