A 467 KB PDF covering the 2SC5066, listed as a schematic but named after a JIS-designated NPN bipolar transistor, so expect a datasheet with ratings, curves and package details. No maker or version is given in the name. A variant file with an FT suffix also exists, so check which package matches the part on your board. Technicians rely on such sheets for pin identification, maximum voltage and current, and finding a suitable substitute. Opens in any PDF viewer.
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.