Hello! Im new here
Dude you need to connect the power supply to gpu from the board like this:
https://drive.google.com/open?id=0B1avZFzVfTQ0NWtaS0xYcWhPMzA
Works for me like charm...
I got the setup done in 30 mins.
I rock on late 2012 macbook pro retina 13 inch intel hd4000 series internal graphics.
TB1->Sonnet EE-> PE4C v3.0 -> GTX 680 with antec 450W power supply.
My switches are on 2 2
https://drive.google.com/open?id=0B1avZFzVfTQ0WmRxUUt0dmFobG8
And here is a proof ow working display hooked through the gfx card
https://drive.google.com/open?id=0B1avZFzVfTQ0N1VFRXFLVHlHQXM