RAR archive of 475 KB covering the ASUS P8H77-M PRO, a micro-ATX board on the Intel H77 chipset. Its contents are not stated in the name, though the size suggests a boardview or schematic rather than firmware. After extraction, use it to locate power stage parts, read net names and pick test points while checking for shorts or missing voltages. Boardview layouts can be viewed in OpenBoardView or comparable software. Confirm that the board revision on the PCB matches the document before using it for detailed work.
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 @boardview. 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.