Small Wistron schematic for a sensor daughterboard, project 18B26, revision A00. The name does not give the laptop brand or model it belongs to. A secondary board like this usually carries sensors, connected to the main board by a flex cable, so the drawing helps when checking the connector pinout, supply voltages and signal lines feeding the sensor ICs. It opens in any PDF reader. Match the board code and revision on the small PCB itself before using the values for diagnosis.
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 @vinafix_bios. 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.