Part number 2SD1424 with an unexplained _E suffix names this 41.4 KB PDF, indexed among schematics but most likely a datasheet for the transistor. The 2SD prefix in the Japanese JIS system denotes an NPN low-frequency bipolar transistor. Technicians read such a sheet for pin configuration, maximum ratings and package outline when tracing a dead stage or sourcing an equivalent. Check that the substitute has the same pin order, and expect the case to show the shortened D1424 marking.
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.