Named only as 2SA1924, this 198 KB PDF sits in the schematic category but most likely holds the datasheet for that part. A JIS designation beginning 2SA marks a PNP bipolar transistor. For repair work the useful sections are the absolute maximum ratings, the hFE classification and the pin diagram. Small packages often print a reduced code, so cross-check the marking against the sheet, and make sure any alternative device matches pin order as well as electrical limits before fitting it.
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.