This 41.1 KB PDF bears the part number 2SA1536 and, although indexed as a schematic, is best treated as the datasheet for a JIS-registered transistor. The 2SA designation stands for a PNP type aimed at high-frequency applications. A technician reaches for it to confirm which pin is which, read voltage, current and power limits, and compare hFE ranges when sourcing a replacement. Verify the printed code and package on the failed device, because similar numbers can come in different cases.
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.