A 152 KB PDF titled with the device number 2SC4443 and grouped among schematics. In the JIS scheme, codes starting with 2SC refer to NPN transistors for high-frequency work, so a datasheet is the most plausible content. The name carries no additional details. Before replacing the part, look up its package and pinout here, check the absolute maximum ratings against the circuit's supply voltage, and verify that the case marking on the board actually corresponds to this type.
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.