PDF for the 2SC4061K, 61.7 KB, filed under schematics though the name reads as a component datasheet. The 2SC prefix follows JIS naming for NPN bipolar transistors, and the K suffix is part of the stated type number; its meaning is not explained by the name, so check the document for suffix-specific details. Use it to confirm pin order, ratings and package outline when replacing or testing the part. Compare the suffix on the actual component as well, since variants can differ.
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.