Boardview for the Lenovo ThinkPad X250 built on the LCFC NM-A091 mainboard, packed as a 2.08 MB RAR. A boardview shows component placement, part designators and net connections on both sides of the PCB, and is opened with viewers such as OpenBoardView, FlexBV or Boardviewer, depending on the format inside. Technicians use it to locate test points, follow a net to a shorted part and find a component referenced in the schematic. Confirm NM-A091 and its revision on the actual 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 @alischematics. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.