A 249 KB PDF dedicated to the 2SA1953, which the JIS scheme classes as a PNP bipolar transistor through its 2SA prefix. It appears under schematics, but a file titled solely by the part code is generally a datasheet. Expect the pinout, package dimensions, absolute maximum ratings and electrical characteristics needed for diagnosing and replacing the device. No manufacturer or revision is given in the name; confirm the printed marking and case type on the board.
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.