The 2SJ344 is covered by this 310 KB PDF, which the catalogue lists under schematics. The file name carries nothing beyond the part number. The 2SJ prefix places it among Japanese-registered P-channel field-effect transistors, so expect a component datasheet rather than a board diagram. A repairer can use the pin assignment to probe the part in circuit, check for a gate-to-drain short with a meter, and choose an equivalent with equal or better voltage, current and RDS(on) figures.
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.