A PDF reference sheet for the 2SD2259 transistor, catalogued as a schematic but in practice a component datasheet of 43.3 KB. The name adds an _E suffix, which only marks a separate edition of the document. Under the JIS naming system the 2SD prefix denotes an NPN bipolar transistor intended for low-frequency use. Technicians open it in any PDF reader to confirm the pinout, maximum ratings and gain before fitting a replacement. Check the package marking on the board against the sheet first.
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.