Roughly 96.6 KB PDF named for the 2SJ308. The name is limited to the part number and provides no model or board reference. Japanese JIS designations reserve 2SJ for P-channel FETs, so this is most likely a datasheet rather than a board-level diagram. It is useful for identifying terminals, checking maximum gate-source voltage and choosing a compatible replacement. Measure the suspect device out of circuit where possible, and keep polarity and footprint identical when substituting.
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.