Covering the 2SD1817, this 75.8 KB PDF is indexed as a schematic but by name is a component datasheet. No maker or revision is indicated. JIS convention places 2SD parts among NPN low-frequency bipolar transistors. The document lets a repair technician confirm the pin order for diode-mode testing, read absolute maximum ratings and gain ranges, and compare packages when searching for a substitute. It opens in any PDF reader. Make sure the marking on the suspect transistor matches before using the figures.
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.