Datasheet-style PDF for the 2SC4271 transistor, catalogued here under schematics and weighing 78.2 KB. The name gives only the part number, with no maker or revision. Under the Japanese JIS scheme a 2SC prefix marks an NPN transistor of the high-frequency class. Technicians use such a sheet to confirm pinout, package outline, maximum voltage and current ratings and gain before fitting a replacement. Check the marking on the actual component, which is often shortened to C4271, and compare the ratings of any substitute.
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.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.