A boardview (component placement) file. Shared as “_GH5KNX1_MB_REVB Boardview (.CAD).cad” — a .cad file, 310 B.
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 @ShareMan_Electronic_Files. Enginerys does not host this file.
How to open a .cad file
GenCAD text export, the usual format for Compal, Quanta, Wistron and Dell / HP / Lenovo laptop boards.
OpenBoardViewFlexBVBoardViewer