Listed under schematics, this 93.2 KB PDF documents the 2SC3685, an NPN bipolar transistor by JIS designation. Only the part number is present in the name, with no variant information. A datasheet of this kind gives pinout, absolute maximum ratings, electrical characteristics and package details. It supports in-circuit diode testing by telling you which leads to probe, and it is the basis for comparing replacement parts. Check the marking on the actual device, since nearby 2SC368x numbers are different components.
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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