Did you find out what causing this issue? I have the same problem, with my 3900x and aorus ultra. he only difference that my pc worked with my rams for 4 days. I tried different rams - same issue. The strange thing is that i get the same error if i didn't put any ram in the mobo I checked the rams in an another pc, they works fine. The PSU also good. I am thinking about RMA the mobo, but first i will buy an another cheap cpu (Ryzen 1200) to test it.