The ECS RS780LQ-CM, board revision 1.0, is covered by this 973 KB RAR archive. Its file name gives no hint of what is inside, so open it to see whether you have a circuit diagram, a firmware dump or both. Schematics in such packages help when following standby and main power sequencing, locating MOSFETs on the CPU VRM, or checking clock and reset signals on a dead board. Compare the revision silkscreened near the slots with 1.0 before relying on part references or values, because layouts change between revisions.
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.