Filed under schematics, a 164 KB PDF named 2N6387 with an RE suffix that the name does not explain. Part numbers with the 2N prefix are JEDEC registrations for discrete semiconductors, and documents like this are typically datasheets listing absolute maximum ratings, electrical characteristics and package details. Use it to identify pins, interpret multimeter readings when testing the device and evaluate equivalent replacements. Any PDF viewer opens it; match the case style on the board with the outline shown.
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.