The 2SC3647 is described in this 141 KB PDF. Its 2SC prefix identifies an NPN bipolar transistor in the Japanese JIS scheme, and the name provides no other information. Most likely the file is a component datasheet listing absolute maximum ratings, characteristic curves and package details rather than a circuit schematic. For repair, it answers which lead is which and what voltage and current the part tolerates, which is essential when sourcing a replacement or cross-reference.
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.