Ethos driving me crazy! Signal lost

[SidETH]

I've build and am running several Windows rigs without too much problems. I want to test Ethos 1.2.7, but can't get the damn thing to even boot up. I'm trying with a purchased version.

1. One 1060GTX gpu connected (2 more installed, but not connected yet)
2. Start up
3. Ethos boot screen is displayed
4. Then blank, signal lost, and the GPU fans turn off

I've tried multiple risers, 3.0 cables, all 3 GPU's individually and simultaneously, pcie speed from auto to gen1 and 2, etc. No differences.
I'm sort of lost here

System is not connected to the internet yet. Shouldn't matter?

Video
https://youtu.be/VRcsq0MX8TA

[SidETH]

Placing 1 gpu directly in the pci16x slot gives the same result. So the risers/cables are not the factor here.
Cards are Asus Dual GTX 1060 O3G.

[SidETH]

Connect the monitor to the motherboard en select internal graphic processor.
Dohh.