Datasheet-type PDF, 180 KB, for the 2SA1899 component, filed as a schematic although the name carries no detail besides the part number. A 2SA designation in the Japanese JIS system means a PNP bipolar transistor. The usual contents are maximum ratings, electrical characteristics, curves and a package drawing. These help verify a suspected failure, locate base, collector and emitter, and pick a cross-reference part. Check the marking and gain suffix on the original device and inspect the surrounding circuit for the root cause.
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.