English-edition style datasheet, judging by the _E suffix common to Japanese maker documents, for the 2SA1748 PNP bipolar transistor; 39.5 KB PDF, filed as a schematic. The name does not reveal the manufacturer. Content should include marking code, package outline, pin functions and electrical ratings. Small SMD transistors are usually identified on a board by that marking, so cross-check it before ordering, and ensure any substitute matches voltage, current and pinout.
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.