Covering the 2SC3547A, this 288 KB PDF is a transistor datasheet indexed in the schematic section. The A suffix identifies one variant of the 2SC3547 base type, and a companion B file exists; the meaning of the suffix is not stated in the name and should be checked in the document. Under JIS rules 2SC means an NPN bipolar transistor for high-frequency use. Look up pin assignment, voltage and current limits and gain here, and verify the printed marking so the correct variant is replaced.
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.