This PDF of 178 KB sits in the schematic category and bears the number 2N6436 plus an RE suffix not explained by the name. Numbers in the 2N series are JEDEC registrations for discrete semiconductors, so the file is most likely a manufacturer datasheet rather than a board diagram. It provides the pin assignment, case drawing and electrical ratings needed to fit a correct replacement or evaluate an equivalent part. Read it with any PDF viewer and confirm the package type on the physical component.
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.