Datasheet PDF for the 2SD1512, 40.8 KB, catalogued in the schematic section. The JIS prefix 2SD denotes an NPN bipolar transistor of the low-frequency type, and the E suffix in the name is not explained. A short sheet like this usually gives absolute maximum ratings, hFE and the lead arrangement. A technician uses it to check the junctions with a diode tester, confirm orientation when refitting the part and compare specifications against possible substitutes.
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.