I replaced my screen with the frame, but after I was done I had no service. After some research I found out that I had bought a new screen for a SM-G780F and not SM-G781B that it should. Everything else is working great. Could it be that the wrong screen is causing the issue? Is the antennas somehow built in with the frame? I have opened the phone up and gone trough my work, and everything seems to be where it´s suppose to be.