The 2SD2648 is covered by this 29.0 KB PDF, indexed as a schematic but in practice a single-device reference. By JIS convention, the 2S prefix indicates a transistor and D an NPN low-frequency type. Repair use centres on reading the pinout and package drawing, confirming breakdown ratings and hFE ranges, and judging whether a cross-reference part is a safe swap. Open it with a standard PDF reader. Small SMD parts often carry shortened marking codes, so match those against the sheet before ordering.
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.