PDF documentation, 311 KB, for the 2SC3121 NPN bipolar transistor, named in the Japanese JIS 2SC style. Though the index labels it a schematic, a single part-number file normally contains the component data sheet. Look for a C3121 marking on the device. The name does not state package, hFE rank or manufacturer. Consult the pinout before in-circuit diode tests, check the ratings against the stage it sits in, and verify outline dimensions so any replacement transistor fits the board footprint.
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.