Radio Problem

Hello guys I have a Skoda Superb mk1 equipped with the skoda symphony radio mp3.The interesting fact is that the radio after a long period of not using it is not starting with the car.If i turn the lights on the display gets green as it should be but nothing is displayed on it.I changed all the fuses even the one in the back of the radio but still i have this problem.The next bizzare thing is that if I turn it on manually and then take the key off and put it back on the radio is turning when I put the ignition.I was thinking about some water in the battery slot to be the problem with it because 2 months ago I did not have this problem.Cheers!