Component datasheet for the 2sb1580, 64.2 KB in PDF and indexed as a schematic. The 2SB prefix comes from the JIS standard and indicates a PNP bipolar transistor for low-frequency circuits; manufacturer and package details are not in the name. Opening it in a PDF viewer gives the pin diagram, collector-emitter and collector-base voltage limits, current capacity and dissipation. Those figures help judge a failure and select an equivalent, provided the marking on the PCB part is first confirmed to be this type.
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.