Covering the 2SJ612, this 29.0 KB PDF sits in the schematic category, though a bare part number usually denotes a datasheet. The 2SJ code in the JIS system belongs to P-channel field-effect transistors, common as high-side switches. Inside you can expect pin configuration, on-resistance, gate charge and maximum ratings, all needed when testing a failed device or selecting an equivalent. No other detail appears in the name, so check the physical part marking and package before use.
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.