Vizio 42in hdtv lcd tv

Question

I don't know if you can answer it or not but I should start out telling you what happened my girlfriend was trying to watch a movie and thought a PS3 charger cable needed to be plugged into somewhere on the TV. So she ended up plugging it into the service port. After that nothing worked not even the led vizio light on the front. So since all of this I've taken the TV apart and seen that the fuse on the power board was blown so I replaced it with a new one. And I contacted a service tech and he recommended to try disconnecting the main-board from the power-board to see if the fuse blows again and it didn't so he told me it was probably just the main-board so I ordered one and installed it and now the led vizio light comes on but nothing else works. Could it be the power board or something else please help thanks.