Small PDF document for the 2SB1537, a Japanese JIS-registered transistor part number, catalogued here as a schematic although a part code like this normally points to a component datasheet. The _E suffix most likely marks an English-language edition. Under the JIS scheme the 2SB prefix identifies a PNP transistor aimed at low-frequency work. Use the sheet to confirm pinout, package outline and maximum ratings before fitting a replacement, and compare the body marking on the board with the part number shown here.
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.