The 2SC4735 is covered by this 109 KB PDF, listed under schematics but named purely by part number. Under Japanese JIS numbering, 2SC denotes an NPN bipolar transistor, so the contents are almost certainly the device datasheet. The name carries no further information. Read it alongside the board you are repairing to verify pin order and package, then check collector-emitter voltage, current and power ratings so any replacement part is equal or better in each respect.
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.