The 2SA1962, a PNP bipolar transistor by its JIS 2SA prefix, is documented here in a 174 KB PDF. Filed as a schematic, it is most likely the manufacturer datasheet. It lets a technician confirm which pin is which, read absolute maximum ratings and characteristic curves, and judge whether an available equivalent will cope with the circuit. Any PDF viewer opens it. No maker, edition or other detail appears in the name, so compare the body marking with the document.
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 @cyberlanelectonik. 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.