For the 2SC3503, a 158 KB PDF datasheet listed with schematics. Only the part number is given; per the JIS system, a 2SC number belongs to an NPN bipolar transistor intended for high-frequency applications. Read it for absolute maximum ratings, electrical characteristics and the package drawing with pin assignment. Those are the values a technician needs to diagnose an open or shorted junction and to approve a substitute. Any PDF reader works. Check the component marking first, as similar codes may refer to different parts.
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.