Only the part number 2SC5108 appears in the name of this 242 KB PDF, which is filed as a schematic but should be read as a transistor datasheet. The JIS 2SC prefix denotes an NPN bipolar transistor, normally marked C5108 on the case. An FT-suffixed version is indexed separately, so confirm the exact marking on your part. The sheet supplies pinout, package outline and electrical limits, useful for diode-mode testing of junctions and for selecting a substitute with adequate ratings.
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.