How can I fix led tv screen with one vertical red line and no picture?

My Seiki tv is currently showing a backlit screen with one vertical red line. (There is no picture so the menu is not accessible to determine if the line shows over or under.) I have already replaced the power supply unit and the t-con board. The tv is not currently plugged up to any hdmi inputs so I know it is not related to this. What else would be causing this problem? How can I fix this?