Larger 319 KB PDF for the 2SC4915, an NPN bipolar transistor numbered under the Japanese JIS scheme. Despite the schematic label, the name points to a datasheet, which at this size probably includes detailed characteristic graphs alongside ratings and package dimensions. Use it to check pinout, compare measured junction behaviour with specified values and pick a replacement with equal or better voltage, current and frequency figures. Any PDF viewer opens it; verify the device marking on the board first.
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.