The 2SK1920 is the only detail in this file name, and the 93.1 KB PDF is indexed as a schematic. Japanese 2SK numbering denotes N-channel FETs, so expect a component datasheet rather than a board diagram. It is useful for checking gate, drain and source pin assignment, maximum ratings and typical characteristics when choosing a substitute. The manufacturer is not stated, so confirm that the logo and package on the faulty part match the document before relying on the figures.
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.