A 169 KB PDF for the 2SD1803, placed in the schematic category but evidently a component reference sheet. No manufacturer, revision or variant is named. In the JIS system, the 2SD prefix identifies an NPN transistor intended for low-frequency service. Use the document to locate base, collector and emitter, read breakdown and current ratings, and check the case style when replacing a damaged part or evaluating an equivalent. Verify the marking printed on the board component matches this type before trusting the data.
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.