For the Delfina the red stripe of the cable has to go to the "end" of the x-surf, the opposite side to the RJ45 interface. That means in an A1200 Elbox Winner Tower with Z4 the red stripe shows to the front of the tower.
Is it clear to you ? If not don't just try cause the Delfina goes up in smoke. So if you power on the Amiga have a look at smoke on the Delfina and power off immediately.
Be careful.