A 152 KB PDF for the 2SD1816 transistor, listed in the schematic section. The name provides the part number only. Under the Japanese JIS naming standard, 2SD denotes NPN bipolar transistors used in low-frequency circuits such as audio, driver and power switching stages. Expect pinout, electrical characteristics, maximum ratings and outline drawings. Use it to verify a suspected failure and to judge whether a cross-reference replacement has adequate voltage, current and dissipation headroom. Confirm the device marking on the board beforehand.
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.