Water Damaged - Screen Flickering At Top

If it suffered liquid damage first thing is to check the extent of it beyond the initial symptoms, as usually this kind of damage tends to progress with time until the phone just dies out of a sudden. Rather than playing a lottery of buying a new screen I’d recommend to better invest the money into professional care where the phone will be taken apart, decontaminated from liquid residues and damage assessed and taken care properly. It would be somewhat more expensive but would be a real long term solution.