The 2SC3689 transistor is the subject of this 89.7 KB PDF, which the catalogue lists as a schematic. As a JIS 2SC number it identifies an NPN bipolar part; the name adds no suffix or revision. Expect absolute maximum ratings, electrical characteristics and mechanical data inside. When a board fault points to this transistor, the sheet lets you verify the pinout, test junctions with confidence and select a replacement whose polarity, package and ratings are at least equal to the original.
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.