Short 31.2 KB PDF for the 2SA1864, a PNP bipolar transistor in the Japanese JIS 2SA family. Apart from the part number the name gives no detail, so expect a compact datasheet rather than the schematic suggested by its type. It serves for confirming pinout and package and for reading key limits such as collector voltage and current when testing or substituting the part. Given the small file size the document may be a brief sheet, so cross-check important ratings before picking a replacement transistor.
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.