Did you test, with skylake, both onboard graphics and PCIE graphics, for all BIOS? If not, please test that way with all BIOS. Then test same way, with whatever BIOS works on Sky, test with Kaby using Onboard and PCIE graphics.
If it can’t boot at all with Kaby, please get 80h debug card and tell us what error it’s stopping on, maybe that could help
The only 2nd bios can work, no problem found with graphics card or Onboard. Every thing was ok. The other can not boot, I’ve tried each a least two times.