This 85 KB PDF is identified by the part number 2SC2314, an NPN transistor under the JIS naming scheme. The index labels it a schematic, though the name indicates a component datasheet. It serves as a reference for maximum ratings, gain and pinout during component-level repair. Before fitting a replacement, confirm that the package matches the board footprint and that the substitute meets the original voltage and current limits, since lead orders can vary.
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)