Reference sheet for the 3SK180 semiconductor in PDF form, roughly 173 KB, catalogued as a schematic. Numbers starting with 3SK follow the Japanese JIS system for four-lead field-effect transistors, a group dominated by dual-gate MOSFETs in RF circuitry. The document should give pin identification, characteristic graphs and limits that help when testing a suspect transistor or choosing an equivalent. It opens in any standard PDF reader; cross-check the package and marking code against the original part before substituting.
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.