The wifi on my phone was not working properly.
The part wasnt perfectly fitted like the parts that came with the phone, even though it was a little difficult getting the wifi plate on it works great now.
If your iphones wifi isnt working properly it can be 3 things the wifi plate, which i got due to the fact that a part of the wifi plate was missing. The bottom speaker has three little metal rods at the bottom make sure all are down none sticking out. And a tiny gold pice of metal at the top side of the mother board that touches the frame, make sure it is touching the frame. Hope this helps!!