Datasheet-style PDF for the 2SD1994A transistor, filed in the schematic category of the index. The 2SD prefix is JIS coding for an NPN bipolar device aimed at low-frequency or power service, and the A suffix normally denotes a variant of the base 2SD1994. The name does not say what the extra E means. Use the 54.7 KB sheet to compare collector-emitter voltage, current gain and package before choosing a substitute, and check the marking on the part on the board.
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.