Lenovo schematic in PDF form, 1.16 MB, named only with the code 80A. That token gives no clear model, board number or revision, so open the document and read its title block to identify the board. Then compare it with the markings silkscreened on the motherboard. Once matched, the schematic helps trace power rails, locate the charging circuit, EC and SPI BIOS flash, and follow signals to connectors during fault finding. A normal PDF reader handles it, with text search for net names.
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.