PDF of 86.5 KB referencing the 2SC4005, categorised as a schematic. By JIS convention 2SC parts are NPN bipolar transistors, and that is all the name reveals; manufacturer and case must be checked inside. Such a document gives the ratings table, electrical characteristics and package drawing that a repair technician needs to identify pins, test the device and select a safe replacement. Since neighbouring numbers in this series can be quite different parts, confirm the marking on the board carefully before substituting.
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.