Part reference for the 2SK242, saved as a 170 KB PDF in the schematic section. Japanese JIS designations beginning with 2SK belong to N-channel FETs, so the file is most likely the device datasheet. No brand or package variant appears in the name. Use it to read pin assignments, voltage and current limits and typical parameters, which help confirm a fault found with a diode-mode meter test and guide selection of a replacement with matching footprint and ratings.
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.