Hi, If it has been wet most likely that screen or board is damaged! However the screen connection has two leads to the mainboard . On is for LCD and other is for digitizer touch glass. When you open the back cover The LCD connector is on the far left coonector just above the battery and digitizer has a very small lead fuether up on left connected under metal cover. You need to lift the metal cover carefully and lift thr connecor latch and the pull the small flat cable. Be carefull this can be damaged if try it hard. Hope this help

This problem is being caused by some loose gap on the back of the screen, to solve this problem, you need to make sure the screen is well secured. To do so, just open the back cover and unscrew the battery cover, then stick some very thin foam over ( & around the edge of the motherboard ), make sure these are not covering the camera, volume button etc .. then screw back the cover gently. This should solve the problem!... if still not fixed fully stick some of the same thin foam under battery which isolates the battery from the screen and fixes the screen and problem should go away!