how can I get my navagation system to start working again? on 2004 Toyota Land Cruiser

My sunroof drain holes were cloged so the computer (Nav system) got wet. The nav system works sometimes , but the display is stuck on milage screan,the radio works but it wont display the channel, the buttons that control nav and heat and air will not work. I have a fan on the computer now trying to dry. Any seggestions

Asked by for the 2004 Toyota Land Cruiser