Covering the transistor 2SC4104, this compact 19.1 KB PDF is tagged as a schematic, but the 2SC prefix in Japanese JIS numbering identifies an NPN bipolar device, so expect a brief datasheet. The file name carries no further details such as manufacturer or package type. A technician would consult it for pinout, voltage and current limits and gain class when diagnosing a shorted or open transistor, and should match the part marking on the board to this number before relying on the figures.
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.