PDF part sheet for the 2SC5577, 40.7 KB, catalogued with schematics. The name gives only the part number and says nothing about the maker or revision. JIS designations starting with 2SC refer to NPN transistors in the high-frequency class. Technicians consult this kind of datasheet to identify base, collector and emitter, look up voltage and current limits and choose an equivalent when the original is obsolete. Compare the C5577 code and the package on the board with the document before swapping components.
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.