Audio not working when recording!?

Ok Here's the deal I have a IPhone 4 and for some reason my mic has stopped working. I have drop my iphone in water but it wasnt fully sumerged. It has been repaired. Now after a day of using my phone something happened. When i record i can't hear any sound whatsoever. But when i put my earphones in i can record and i can hear the audio well. I dont know why this happen. I can hear music very well. I can use voice memos very well. Voice command works very well. I have looked at Youtube and Google for help but they all say to take it apart and i really don't want to do that and then cause more damage. Please Help Me!!!