I have sound but no picture, after replacing x-main board.

Hi, I have a Samsung Plasma Tv, 42 inch, PN42B450B1D. It sustained water damage while on. The water fell (if you are facing the rear of the tv) on the right hand side of the tv. The result was that it lost its picture and when you try and turn it on, it just clicks several times, but does not switch on. The red light in the front was on. So after checking the two boards, x and y, I thought is was the x main board because if I unplugged the y board the tv made the start up sound, but when I only had the x-main plugged in (no y board), then everything was dead. So I replaced the x main board. Now the tv starts up, with sound, but no picture. The green LED light flickers every second. It can change channels and everything, but no picture. Any ideas where the problem might lie. Just important to note. The fuses on the power board are just fine. I can't see any visible damage to capacitors.

Thanks for any help.

Christine