Schematic in PDF form, 918 KB, named after P552LJ, which looks like a notebook model designation; the RG suffix is not explained in the name. No board number or revision is given, so the motherboard version cannot be confirmed from the file name alone. Technicians use such diagrams to follow power rails, check enable signals and locate faulty components around a short. Open the PDF and read the title block, then compare the board number and revision printed on the PCB before relying on part values or connections.
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 @hrtechno. 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.