Drone not connecting to the assistant software to diagnose problem

I got a DJI phantom 2 and i crashed it into water. it was in the water for brief time and i dried it and cleaned it, but the battery got damaged and i replaced it. it still did not work, but now the drone starts peeping and lighting but the motors wont start. i tried to connect it to the assistant 2 software from DJI to figure out whether it is the ESCs or the motors, but the software does not connect to the drone. What might be the issue here, is it the mother board?