At 526 KB, this PDF for the 2SC1923 is larger than most single-part sheets in the set, possibly including more curves or package options. The JIS prefix 2SC identifies an NPN bipolar transistor, so treat it as a datasheet despite the schematic label. Look up pinout, absolute maximum ratings and gain ranking when diagnosing or replacing the device. The name does not specify maker or package, so confirm the markings on the component and match the outline before using the lead assignment.
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.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.