Lowercase-named PDF of 136 KB covering the 2SK2503, catalogued as a schematic though it relates to a single transistor. JIS naming assigns 2SK to N-channel field-effect transistors; manufacturer and package are not given. Another version with a _1-5 suffix is indexed alongside it. Open it in a PDF viewer to review pinout, absolute maximum ratings and the package outline, which helps when testing a suspect device or picking a substitute. Match the printed marking first.
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.