Indexed as a schematic, the 124 KB PDF named 2SJ193 most probably holds the datasheet for that JIS-numbered P-channel FET. Expect a rating table, electrical characteristics and a mechanical outline. When a P-channel switch or amplifier device fails, technicians consult such a sheet to identify pins, compare an equivalent and check that dissipation and voltage limits are sufficient. The file name provides no maker or package details, so match the part on the board before ordering a replacement.
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.