A 35.0 KB PDF referencing the 2sk2574, listed with schematics but named solely by its part number. Under JIS naming, 2SK means an N-channel FET, so the file is most plausibly a compact manufacturer datasheet. It should give pinout, case outline and maximum ratings, all useful when verifying a suspected failed transistor with a multimeter or locating a substitute. Open it in a standard PDF viewer and make sure the printed code on the installed part matches before trusting the data.
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.