Sony VAIO laptop schematic in PDF form for the MBX-202 motherboard, with M790 also in the name, likely a related model or project code, in a 779 KB file. MBX numbers are Sony's own mainboard identifiers, printed on the PCB of VAIO notebooks. The diagram helps trace DC input and charger circuits, standby rails, CPU and chipset supplies and power-on signals when a unit is dead or shuts off. Open it in any PDF reader, and check that the board reads MBX-202 before trusting component references.
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.