Reference sheet in PDF form (150 KB) for the registered semiconductor number 2N6804, catalogued under schematics. Nothing in the name points to a specific product, board or revision; it is simply the part code. The JEDEC 2N scheme covers discrete devices such as transistors, so expect datasheet content: electrical characteristics, maximum ratings and package drawing. Use it to verify a substitute before soldering it in, and check the part marking and case style on the board against 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.