The 2SC3144 NPN transistor is documented in this 117 KB PDF, filed as a schematic though it is most likely a component data sheet. The 2SC prefix follows Japanese JIS part numbering, with the body usually printed C3144. Inside one would expect ratings, electrical characteristics and an outline drawing. When diagnosing a dead stage, use it to identify pins for diode-mode testing, verify the package fits the pads, and ensure any substitute meets the voltage, current and power figures listed for the original.
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.