Can recieve/send calls/texts, but no data connection

I have contacted my provider and Samsung, they want me to send them my phone and pay $80 for them to look at it. I should be able to fix this problem myself. About 4 months ago my screen broke and i ordered another screen offline, i replaced it myself, using all the correct tools and ensuring that I put everything back the way i removed it, even the number of times i turned a screw to remove it. Before my screen broke I had perfect 4G connection, after I replaced the screen I had connection for about an hour then it disappeared. The only troubleshooting item I haven't been able to do was ensure my IMEI number was correct, but instead of numbers I have a series of stainge symbols. Can someone help me get my data back?