Reference PDF for the 2SK620, a JIS-series N-channel field-effect transistor, weighing 35.6 KB and listed under schematics though it is most likely a datasheet. Nothing beyond the part number is stated in the name. Typical contents are pinout, maximum voltage and current ratings and characteristic curves. A technician consults it to verify orientation, test for drain-source shorts, and pick a suitable equivalent when the original is unavailable. Open it in any PDF viewer and check the package against the part on the board.
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.