Lines that appear in this fashion can often be resolved by a simple re-seating of the cables that go to the panel. The voltage/current levels of the signal lines is so small that it doesn't take much dirt or corrosion to prevent data flow. Re-seating the cables can resolve this. If the simple re-seating does not resolve the problem, try applying heat or cold to the area on the T-con board. This too can show poor connections or a defective IC to confirm the location of the problem.