A 708 KB PDF indexed under schematics and named only with the part number 2N5771, with no board, revision or device given. The 2N prefix is the JEDEC registration scheme for discrete semiconductors, so the file is most likely a component datasheet, not a board diagram. Technicians use such a sheet to confirm pinout, package, polarity and maximum ratings before fitting a substitute. Check that the marking on the faulty part really matches 2N5771, because similar codes can hide different devices.
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.