Covering the 2SC4612, this 155 KB PDF is indexed as a schematic but is in practice a transistor datasheet, as only the part number appears in the name. Under JIS conventions 2SC marks an NPN device for high-frequency applications. Repair work benefits from its pin diagram, absolute maximum ratings and package outline when checking a component in or out of circuit. Verify the printed marking on the original part and its package before trusting the sheet or ordering a replacement.
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.