A 115 KB PDF named after the 2SD1625 part number, catalogued as a schematic but in practice most likely the transistor's datasheet. Parts with the 2SD prefix follow the Japanese JIS scheme for NPN low-frequency transistors. Repair work benefits from the pin assignment, package drawing and absolute maximum ratings, which let you test the part with a meter in diode mode and pick a suitable equivalent. The case print normally drops the 2S, so look for D1625 on the board when locating the device.
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.