The name of this 97.3 KB PDF gives nothing beyond 2SJ277, a JIS-style designation in which 2SJ marks a P-channel FET. Although the index lists it as a schematic, the content is most likely the datasheet for that single transistor. It is useful when a damaged switch in a power stage or audio amplifier must be identified, tested or replaced, since it lists the gate threshold, drain-source limits and package outline. Compare the case marking on the board with the sheet before ordering a substitute part.
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.