Device documentation for the 2SJ144 as a 293 KB PDF, catalogued as a schematic. A 2SJ number in the JIS system denotes a P-channel FET, so the file is most likely its datasheet with ratings tables and characteristic graphs. Technicians check such sheets to identify pins, confirm breakdown voltage and current capability, and select a matching P-channel replacement. Compare the package outline in the document with the part on the board before ordering anything.
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.