Compact 29.7 KB PDF for the 2SD2649, placed in the schematic section though the name indicates a component datasheet. Beyond the part number the file name carries no further details such as maker or revision. JIS designations beginning with 2SD belong to NPN transistors intended for low-frequency circuits. The sheet helps when locating collector, base and emitter for in-circuit tests, comparing voltage and current limits, and checking the package type. Verify the device marking on the PCB matches before relying on the listed figures.
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.