Wifi won't work on water damaged Iphone 5s

I recently water damaged my iphone 5s and couldn't get it to turn back on. After placing the phone in rice for over a week I tried charging it and by some miracle it turned on. Now the wifi on my phone is greyed out and I don't want to try blow drying it, then freezing it because I'm pretty sure that only works for a little bit and can damage the screen. How do I fix my wifi problem? Also the phone is disconnected from my service provider (sprint) so it has no internet access at all.