Datasheet for the 2SB1539 PNP transistor as a 40 KB PDF; the _E suffix most likely marks the English edition of the document. The JIS 2SB prefix covers PNP bipolar transistors for low-frequency applications, and the name does not state maker or package. Use it to look up lead order, absolute maximum voltage and current, power dissipation and gain ranking when diagnosing a failed stage. Read the marking on the board part to confirm the type, then pick a replacement matching polarity, package and ratings.
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.