2SC5154 is the only detail in this 198 KB PDF name, and that JIS designation points to an NPN bipolar transistor of the high-frequency group, so treat the file as a datasheet even though it is categorised as a schematic. Manufacturer and package are not stated. Technicians rely on such documents for lead identification, voltage and current ceilings, dissipation and hFE grading. Before swapping parts, compare the case style and marking on the board with the drawings inside the document.
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.