PDF schematic labelled only as Lenovo U350, with no board number, ODM or revision mentioned in the file name. The 615 KB size suggests a compact document, so check its title block for the project name and board number before use. A laptop schematic like this is used to trace power rails from the adapter input through the regulators, follow enable and power-good signals, and confirm resistor and capacitor values around a fault. Make sure the board number printed on your mainboard matches the one in the drawing.
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 @pepeelectronica. 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.