Boardview file in BRD format, named LI6J with no brand, model or revision given, so the board must be identified by matching that code to the PCB marking. At 168 KB it contains component outlines, pin locations and net connections. Technicians open .brd files in boardview software such as OpenBoardView or FlexBV to locate parts, find test points and follow a shorted net to the failing component. Verify the board code and revision on the PCB before trusting the layout, as similar names may belong to different boards.
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 @pepeelectronica. Enginerys does not host this file.
How to open a .brd file
The most common boardview extension. Several unrelated formats share it, which is why one viewer opens a .brd and another refuses it.