Reference PDF for the 2SA1923 transistor, 195 KB, catalogued as a schematic though nothing in the name beyond the part number indicates more than a datasheet. JIS numbering reserves the 2SA prefix for PNP bipolar transistors. Expect tables of ratings and characteristics plus a package outline, handy for confirming pinout and choosing an equivalent. Before replacing the part, check neighbouring resistors and the drive circuit, and confirm the body marking and orientation against the drawing 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.