iPhone 4 GSM A1332 HW related boot loop PLEASE HELP!

Hello experts,
I am experimenting with a friends old iPhone 4. He said it wont turn on because it fell in water, but he pulled it out super quick. I took the logic board out and cleaned it with iso alcohol then let sit in rice for 24 hrs. I put it in, and still no dice. Well, this cable in the middle of the 3 flex cables that are all in a row (PM for a image) above the battery accidentally came out, and the Apple logo came on, but it started looping (tried this with battery out and in). prntscrdotcom slash augfaq is the image of the cable. I tried plugging it back in when the apple logo came on, but it just stayed on it. From what I gathered, it is just a headset speaker connection. Could someone please help me out?