A 117 KB PDF catalogued as a schematic but named after the 2SK1458 part number, so it most likely holds the manufacturer's data sheet for that semiconductor. Under the Japanese JIS numbering system, the 2SK prefix marks an N-channel field-effect transistor. The name gives no other details, such as package or maker. Technicians use such sheets to check pinout, voltage and current ratings and on-resistance before fitting a substitute. Confirm the marking on the failed part before trusting the document.
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.