PDF document of 9.45 MB catalogued as a schematic, with the name GA1021-B and the note PCB. The name does not state a brand, a device type or a revision beyond the B suffix, so the hardware it covers has to be confirmed by comparing it against the physical board. Technicians use such drawings to trace power circuits, find connector pinouts and locate the components around a fault. Any PDF reader opens the file. Before relying on part values, check that the identifier on the PCB matches GA1021-B exactly.
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 @videocard_notebook_resistance. 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.