A 407 KB PDF for the 2SK2602, a part number following the Japanese JIS convention in which 2SK designates an N-channel field-effect transistor. The file is grouped with schematics, yet nothing in the name refers to a board or product, so it is presumably the component datasheet. For repair, the useful parts are the pin diagram, package drawing and absolute maximum ratings, which guide in-circuit testing and safe substitution. Verify the code printed on the transistor body before ordering an equivalent.
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.