Start by checking the supply circuits for short circuits and the correct voltages. I had several boards in the repair, in which the protection transistor CPU Vin (1.7-2.2v) broke through. In addition, to be sure that hub x99 is working properly, you need check the filtering capacitors on the chip itself (there are about 10 of them). None of them should be punctured (the capacitors themselves are in good order, but the x99 chip is dead inside). And only after all the voltages on the board are present, mio responds, the BIOS is flashed, the hub is alive, we can say that the ROG chip may be faulty. In general, I have two boards at home (RVE & R5E10, both are already working and tested) that had different faults, but the ROG chips are working.