Screen Replacement connectors and cable ribbons

Okay so I cracked my surface pro 4 screen a while back and just now got around to replacing the screen. I successfully removed the old screen and all of the glass and took off the n-trig board. I even took off the ribbon cables from the screen and the motherboard and set them aside. I picked up the new screen and reattached the n-trig board to the new screen. I continued with my repair and attached the ribbon cables to the new screen and then attached the other ends to the motherboard. After this I powered on my device and it worked! So after testing the touch and pen I decided to unplug the ribbon cables from the motherboard so I could re apply the glue for my screen to stay on. Well before I put on the glue I decided to test out the display one last time but when I plugged in the cables the display did not turn on. I double checked all of the connections and everything was secure. I even unplugged and plugged back in all of the cables. When this did not work I decided to buy all brand new cable ribbons and another screen replacement and I still get no display. However the surface still works because it recognizes my face still ( the red light at the top shuts off when I face the camera) and it still makes sounds. Somebody please help me figure out why I'm not getting a display anymore. I've more than triple checked everything and I can't get a display.