Filed under schematics, this 65.3 KB PDF is named only for the 2N5191 part number, so it is almost certainly a component datasheet rather than a board drawing. The 2N prefix belongs to the JEDEC registration system for discrete semiconductors. A technician would open it in any PDF reader to confirm the pinout, maximum voltage and current ratings and package outline before fitting a replacement, and should compare the case style and markings with the part removed from the board.
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.