The 2SA1525 transistor gives its name to this 30.8 KB PDF, which is filed as a schematic but presumably contains the datasheet. In JIS numbering the 2SA prefix denotes a PNP device intended for high-frequency operation. The document is handy for checking pinout and package outline, reading absolute maximum ratings and gain classes, and assessing equivalents when the original part is unavailable. Make sure the marking and case on the board match this part before relying on its specifications.
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.