Small PDF named after the APL5930, an Anpec low-dropout linear regulator used on notebook boards for low-voltage rails. The file is most likely the chip datasheet rather than a full board schematic, and no laptop model is named. It gives the pin assignment, the enable and power-good behaviour, and the formula for setting the output voltage through the feedback resistors. That helps when measuring an LDO that is missing its output or running hot. Check the package marking on the board against the datasheet, as several package variants exist.
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 @schematics_boardviews. 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.