Part number 2SC2851 with an _E suffix names this 48.7 KB PDF, listed as a schematic. The 2SC prefix follows JIS numbering for NPN bipolar transistors, so a datasheet is the likely content; the name does not explain the suffix, which may simply mark an edition or language version. Repairers use such sheets to confirm lead order, voltage and current limits and gain grading. Verify that the package and marking of the part on the board match before choosing an equivalent on the basis of these figures.
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.