Indexed as a schematic, this 55.8 KB PDF actually names a discrete part, the 2SC3930, followed by an _E suffix. JIS designations beginning with 2SC refer to NPN transistors, generally high-frequency devices, so treat the file as a component datasheet. It supports tasks such as confirming pinout before desoldering, comparing gain and voltage ratings with a replacement, and identifying the package from its outline drawing. The name gives no further details, so match the marking code on the actual part before relying on it.
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.