The 2SK1747 is the subject of this 184 KB PDF. Japanese JIS designation 2SK means an N-channel field-effect transistor, so the file is probably the manufacturer datasheet, although it is filed under schematics. It should show absolute ratings, characteristics and the outline with pin numbering. Use it to confirm gate, drain and source orientation, check limits and evaluate substitutes. The name provides nothing about package or maker, so confirm those from the component on the board before ordering parts.
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.