There is a chance that the WiFi antenna was damaged during the replacement. The antenna is located in the top right corner of the housing, right by where a pry tool will go for removal. Try having whoever replaced your screen replace that as well, because that repair person is at fault here.

If you have no response on the screen and you home button is not working, plug it into the a computer with your Itunes account on it. Then just restore to a backup from before you flipped the settings. That should fix your issue.