Component reference PDF, 139 KB, for the 2SA1778. The type field calls it a schematic, yet the name follows Japanese JIS numbering, where 2SA stands for a PNP bipolar transistor, so expect a datasheet. Nothing else is stated in the name. Useful content will include absolute maximum ratings, characteristic curves, package outline and marking. Use it to verify pinout before measuring junctions, and confirm the package on the PCB matches before ordering a replacement.
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.