Part data for the 2SC4686A in a 208 KB PDF, catalogued with schematics. JIS numbering marks 2SC as an NPN bipolar transistor, and an A suffix normally points to a revised or improved version of the base number, so do not treat it as interchangeable with the plain 2SC4686 without comparing figures. A repairer uses the sheet for terminal identification, case outline and limit values. Confirm the exact marking on the failed component before choosing a replacement with matching or higher ratings.
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.