Reference PDF, 99.3 KB, for the 2SC3994, listed in the schematic category but named like a transistor datasheet. Under JIS numbering, 2SC parts are NPN bipolar transistors; no further details such as manufacturer or case appear in the name. The usual use is reading pinout and absolute maximum ratings to test a failed device and to select an equivalent with at least the same voltage and current capability. Open it in a PDF reader, and verify the code printed on the actual component before substituting.
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.