Did you flash the cards with the wrong bios? That looks like corrupted graphics card bios, and the only way that could have happened to ALL 7 CARDS is if you did it.
We could only run windows with the onboard.
The GPUs are brand new and haven't been modded. At no time the GPUs were acknowledged by the motherboard, so we didn't even get to biosmoding the GPUs.
Plugging only one gpu into the X16 slot, and the TV's HDMI to the GPU, gives that colourized "rainbow screen", and the Motherboard Explorer says the X16 slot is "empty".
could it be some sort of incompatibility with the MSI z170A Titanium edition and the RX 570 Sapphire pulse 4 Gb cards? Sounds very unlikely, but who knows