PDF document of 171 KB for the 2SD1314, indexed as a schematic although the part number points to a component datasheet rather than a board drawing. Under the Japanese JIS scheme, the 2SD prefix marks an NPN bipolar transistor intended for low-frequency use. Such sheets list absolute maximum ratings, hFE gain groups, package outline and pin order. Technicians use them to check a suspected shorted transistor or pick a substitute, comparing voltage, current and power ratings and confirming the pinout before soldering.
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.