Part number 2SC4840 names this 468 KB PDF, which the index lists as a schematic. Following JIS conventions, the 2SC prefix marks an NPN transistor, so expect datasheet material such as pin diagrams, maximum ratings and characteristic graphs; no brand or package is mentioned. The document serves for in-circuit diagnosis and for confirming that a substitute part has adequate voltage, current and dissipation ratings. Any PDF viewer opens it; confirm the component marking before trusting the match.
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.