Listed under schematics, the 37.8 KB PDF 2SA2040 is named for a single semiconductor, a PNP bipolar transistor according to the JIS 2SA prefix. The name does not reveal the maker, package or any revision, so the document should be opened to confirm the details. Technicians use such a sheet to read the pinout before probing, to check absolute maximum ratings against the circuit, and to verify the SMD marking code so the correct transistor is ordered.
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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)