The smallest sheet of its group at 24.4 KB, this PDF concerns the 2sk2573, an N-channel field-effect transistor by the JIS 2SK prefix. It is indexed as a schematic, though the name contains only a part number and likely holds a one-page datasheet. Use it to read pin order and headline ratings such as drain-source voltage and drain current when testing or replacing the device. Detail may be limited, so confirm the marking and package on the real part before choosing a substitute.
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.