Compal LA-9301P mainboard schematic, a 2.07 MB PDF whose name includes the marking r10, most likely revision 1.0. The laptop brand and model are not given. Compal's LA-xxxxP numbering identifies the PCB design, which may appear under different notebook brands. Technicians use a diagram like this to measure power rails against expected values, trace enable and power-good signals and locate the component behind a short circuit. Compare the board code and revision printed on the PCB before trusting the pinouts and component values.
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 @notebookschematic. 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.