PDF for the 2SJ306, about 94.4 KB. The name contains just the transistor type, so no device, board or revision can be stated. Under JIS numbering the 2SJ prefix means P-channel FET, and the content is most likely a datasheet with ratings and a package drawing. Use it to identify gate, drain and source before probing and to assess whether a replacement candidate meets the required voltage and current. Keep the same polarity and case outline to fit the existing PCB pads.
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.