Datasheet PDF, 81.8 KB, for the 2SC3997 transistor, placed in the schematic listing. JIS numbering uses 2SC for NPN bipolar transistors; nothing else, such as maker or case, is given in the name. The document should contain ratings, characteristics and a mechanical outline. Repair technicians rely on these when testing a transistor that may be shorted, identifying its legs and looking for an equivalent with equal or better voltage and current handling. Confirm the marking on the PCB part matches before using the data.
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.