Water Damage Only Stopped My Reciever

I dropped my phone in the water and the strange thing is everything works mechanically about the phone just as it should, I just don't get a signal anymore and can't make calls. I get no service but I can still operate off of the wifi. Basically its just an Ipod now. My question is I want to know what piece it sounds like I need to repair. I doubt that the phone is scrap and I don't want to buy a whole new one when the chances are it can be a simple fix!