Gopro will not turn on..

In Aug. 2016 my gopro fell into a river without its housing and stayed under for about 30-45 seconds. When I recovered it, I removed the battery, drained the water i could and left it in the sun until i got home, where i put it into rice. It should be noted that the device did turn on when i first tried it after it was in the river. Now months later it still wont turn on.. what do you think the problem is, what should I replace? If anything...