Datasheet PDF, 43.0 KB, for the 2SD2321, with an _E suffix carried over from the original name, though the suffix itself is not explained. The 2SD prefix under JIS numbering identifies NPN transistors for low-frequency applications, which explains why a part document appears under the schematic category. Technicians check pin assignment, voltage and current limits and power dissipation here before substituting a failed part. Any PDF reader opens it. Make sure the package and marking of the original device match the datasheet.
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.