Component documentation for the 2SC3686, packaged as a 92.3 KB PDF and filed as a schematic. The 2SC prefix follows JIS registration and denotes an NPN transistor; the name gives no suffix or version. Inside, look for maximum voltage and current ratings, characteristic graphs and outline dimensions. These figures are what you need when replacing a burnt transistor: confirm the pin arrangement on the PCB footprint, verify polarity and choose an equivalent that meets or exceeds the listed limits.
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.