Small 89.2 KB PDF labelled 2SJ191, a JIS designation that marks a P-channel FET, so the file is presumably that part's datasheet rather than a board schematic. It serves for checking lead assignment, polarity and absolute maximum ratings during component-level repair and for comparing candidate substitutes. Open it in any PDF reader. Because the name does not give the maker or package, make sure the device on the board carries the same marking and case style before relying on the data.
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.