The 2SK1886 is the part covered by this 96.2 KB PDF, indexed in the schematic section. With a 2SK prefix from the Japanese JIS scheme, the device is an N-channel FET and the file is most likely its datasheet. Use it for pin identification, maximum drain-source voltage and current, and package details when diagnosing a failed transistor or comparing candidate substitutes. No brand or package is named, so confirm the marking on the original component before relying on the specifications.
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.