LG tv problem.

Hello, Dave here. New boy. I'm hoping someone can help with the following question
LG 42LV355U 42” led tv 4 yr old

While watching TV a vertical white band about 6 inches wide suddenly appeared and the rest of the screen lost brightness. Blues and purple affected the picture. I tried switching HDMI cables but no luck as it still showed on my Playstation reception. I spilt some liquid on the screen about an hour before this problem started though only a small amount.
Is this a problem anyone has experienced or offer any suggestions....