A larger 213 KB PDF named 2SD1415A, listed under schematics but realistically the datasheet for that transistor; the A suffix denotes a variant of the base 2SD1415 part. In JIS nomenclature, 2SD covers NPN bipolar transistors for low-frequency applications. Check ratings, curves and package drawing when replacing it, and do not assume suffixed and unsuffixed versions are interchangeable without comparing their limits. The body is often stamped D1415A.
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.
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