Carrying only the part number 2SD1885, this 93.4 KB PDF is filed as a schematic, though it reads as a transistor datasheet by name. Under JIS, 2SD means an NPN transistor for low-frequency applications. The sheet should give pin configuration, ratings and package details, which a technician uses to confirm a failure with a multimeter and select a replacement with equal or better voltage and current limits. Any PDF viewer will open it; the component is commonly marked D1885.
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.