Reference sheet for the 2SC5298 in a 95.7 KB PDF. Parts with the 2SC prefix are NPN bipolar transistors under the Japanese JIS numbering system, so the content is likely a datasheet rather than a circuit diagram. It should list collector-emitter voltage, collector current, power dissipation and pinout. Repair technicians use such data to check a failed transistor with a multimeter and to select an equivalent with matching or higher ratings. Verify the package type against the part fitted.
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.