Schematic file labelled QU1, a 764 KB PDF with no further detail in the name. The code may be a Quanta-style project designation, but no board number, revision or laptop model is stated, so read the title block inside the document to confirm what it covers. After matching it to the code on the PCB, a technician can use it to follow voltage rails, check enable signals, find where the BIOS and EC chips connect and identify components to test on a shorted line. Any PDF viewer opens it.
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.