RAR archive for the Quanta RM5 motherboard at revision D3A, no device brand stated in the name. Around 1.10 MB, it probably carries a schematic, perhaps alongside a boardview usable in OpenBoardView or FlexBV. Technicians use these to find components and test points, measure rails in sequence and isolate shorted parts. Quanta designs boards for many laptop makers, so confirm the RM5 code and the D3A revision printed on the PCB before taking voltages or component values from the file.
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 @IT_SERVICE_WORLD. 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.