The 2N5087 is the only detail in the name of this 100 KB PDF, catalogued as a schematic but most likely a part datasheet. The 2N designation comes from the JEDEC registration scheme for discrete semiconductor devices. At the repair bench it is useful for reading the pinout, maximum ratings and characteristic data before ordering or fitting a replacement. Make sure the package style and lead arrangement described match the device removed from the circuit.
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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)