Data sheet style PDF, 103 KB, for the 2SC3149 NPN bipolar transistor named under the JIS 2SC scheme. On the board the device will typically carry the shortened marking C3149. The name says nothing beyond the part number, so package type and gain classification must be read inside the document. Use the pinout to orient meter probes for junction checks, confirm the footprint before ordering a part, and compare the rated voltage and current with the circuit before fitting a substitute transistor.
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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