The 2SK1434 N-channel field-effect transistor, named according to the Japanese JIS scheme where 2SK signals that device class, is documented in this 104 KB PDF. Although filed as a schematic, a single part number usually means a datasheet. No package or rating information appears in the name itself. Open it in a PDF viewer to confirm terminals and limits, then use those figures when diagnosing a failed switching transistor or confirming that a proposed replacement is electrically compatible.
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.