Named after the transistor 2SA2059, this 183 KB PDF most likely holds that component's datasheet, despite the schematic category. In JIS numbering the 2SA prefix identifies a PNP bipolar transistor. The name gives no manufacturer, package or ratings, so open the document itself for those. Repair use is typical: check the pinout before testing with a meter in diode mode, compare the absolute maximum ratings when choosing a substitute, and match the package outline to the footprint on the PCB.
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.