PDF for the 2SK1739A, 197 KB, listed as a schematic. The 2SK prefix follows the Japanese JIS designation for N-channel field-effect transistors, and the trailing A suffix marks a variant of the base 2SK1739 number. Expect datasheet content: ratings, characteristics and package outline with pinout. Because suffixed versions can differ from the base part, confirm that the marking on the component includes the A before relying on these values. Use it to test a suspect device and qualify a replacement.
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.