Named 2SC3940 with an _E suffix, this 51.7 KB PDF sits in the schematic index but is a transistor datasheet by all appearances, the suffix usually denoting an English version. The 2SC prefix follows the Japanese JIS scheme for NPN bipolar transistors. Technicians use such sheets for pin order, maximum voltages and currents, and gain classes when diagnosing or replacing a part. Nothing else is stated, so compare the C3940 code and case outline on the component before relying on it.
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.