Uninstall from the rig all of the hard drives and leave the USB installed on the rig. it should prompt DOS. make sure you have the correct BIOS and you should be good.
if for some reason you cannot boot with video just type “F” and wait like 5 minutes. At that point, since you cannot see a thing, you should assume that the Bios was updated.
I spoke to my seller and china and she spoke to the factory. after you update the bios, you need to execute the following command.
sed -i 's/ pci=noaer / pci=noaer,nocrs /g' /etc/default/grub && update-grub;reboot
after that, reboot and you should have access to all the GPUs. I was able to apply it to all my Rigs and it works!!