My water damaged 6s won't turn on

I have a iPhone 6s that dropped into water. We have tried a lot of things to try to fix it. We put it into rice, and then we took it to a repair shop, they said the board was bad. But later we found out that they hadn't even opened up the board to look. They also broke a wire hooked up near the speaker and running right up to the LCD screen hook up, which we think is a cellular cable. The other day we soaked it in isopropyl alcohol for house and shot water through the boards and such, after we got all the water out we plugged it in, nothing. We could feel a very normal amount of heat where the battery input to the board was. But not near as much a before. Any ideas on how to fix this, maybe the capacitor, chip? I have no idea anymore. Thanks!! Caiden