Indexed as a schematic, this 96.7 KB PDF is named for the 2SC3086 and most likely holds that transistor's datasheet. In JIS semiconductor numbering, 2SC stands for an NPN bipolar transistor built for high-frequency applications. Technicians consult this kind of document for the package pin layout, breakdown and dissipation ratings, and hFE bins. These figures matter when swapping in an equivalent. Confirm the body marking and any trailing suffix letter against the failed part before buying a replacement.
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.