Small RAR archive of 120 KB labelled only AT6-D, with no brand, model or document type stated in the name. AT6 resembles a project code style used by some laptop ODMs, but the exact device cannot be confirmed from the name alone. At this size the archive most likely holds a firmware dump or a compact boardview rather than a full schematic. Extract it and inspect the contents before use, and compare any board number found inside with the marking printed on the PCB before relying on the data for diagnosis or flashing.
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 @ITHINKHS. 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.