The 86.7 KB PDF named 2SC4572 is filed as a schematic yet carries a transistor part number, so expect a component datasheet rather than a circuit diagram. In the JIS scheme, 2SC indicates an NPN bipolar device intended for high-frequency use. The name gives no vendor or revision. Consult it for lead assignment, maximum collector-emitter voltage and current, hFE range and package outline, and confirm the marking on the physical part matches before trusting its pinout during testing.
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.