Problem description doesn't looks very good.
Was there a reason not to use the latest BIOS for the DH77KC (v 105)? The release notes do mention a couple of memory fixes between v95 and v105. One of them may cause the issue you see.
- You could try the BIOS recovery procedure (see manual) to load v69 or v105.
- You could disconnect everything not really needed to boot the board into the BIOS (connect the video output to the onboard video and removing the video card)
- Changing the order of the memory modules may trigger an memory re-init. 1 module in different banks.
- Alternative: borrow some memory module to see if a different module can bring the board back to live (and then upgrade\downgrade).