Compact RAR archive for the Asus N53TA laptop mainboard, revision 2.0 according to the name. At 152 KB it is probably a boardview or small service file rather than a full schematic PDF, so check the contents after extraction. Asus uses the model name as the board identifier, and the 2.0 revision printed on the PCB must match. Technicians use such documentation to locate components, check rails at test points and trace the power-on path when the laptop shows no power, no charging or no display.
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 @cidschematicandboardviewofficial. 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.