Update on my black screen issue. (No video output at all from power on.)
I did RMA my original 3080 FTW3 Ultra and received the replacement GPU. I installed it and that card had the same issue. I was pretty ticked at that point, but as a last ditch effort, I decided to take out my vertical mount and install the card directly to the MB. The card worked flawlessly. Problem solved. I never gave the vertical mount a thought because my 2070 worked fine with it. I knew the riser cable was Gen 3 not Gen 4, but my understanding was that it should work. Yesterday I decided to check Amazon and see if there were any Gen 4 cables available. There are, but in reading the questions and reviews I found that many other people have had the same issue with the 30 series cards. I did purchase a new Gen 4 cable that is reported, by users, to have fixed the issue. Just updating so that others having the same issue have a possible solution. I didn't see anything on any forum with this information