Named solely 2SC4843, this 469 KB PDF belongs to the schematic section but almost certainly describes a single component: the Japanese JIS prefix 2SC identifies an NPN transistor. No manufacturer, case or specification is stated in the name. For repair work, the datasheet gives pinout, voltage and current limits and gain figures used to verify a suspect part and qualify a substitute. Open it in a normal PDF reader and check the printed marking on the board before ordering.
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.