For the 2SC4742 transistor, this 32.2 KB PDF is indexed under schematics yet appears to be a component reference. Following JIS rules, the 2SC prefix marks an NPN bipolar part, and the name gives no suffix or variant. A document of this kind lets a repairer read pin assignments, case type and limit values, useful when a power supply or deflection stage has a dead transistor. Measure junctions with a meter, verify the marking on the original, and pick a substitute whose voltage and current ratings are not lower.
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.