red light on when phone is turned on

My phone fell into a drink for only 2 or 3 seconds before being retrieved. I have taken the phone apart, dried it, cleaned it with a tootbrush and rubbing achohol, and replaced the battery with a samsung original replacement. The red light on the top left of the S III screen, just left of the samsung name, lights up whenever i turn on the phone and remains on as long as the phone is on? The screen will also go dark when making a call from the key pad unless i activate the speakerphone function immediately after touching the call button. Do you have any suggestions?