|Exactly what mine looked like|
The solution is on the AVS Forums and the link is provided below, however here is the process. This will only fix your vertical lines if they look like the image above and jiggling or tapping the back panel of the HDMI connection area makes the lines go away.
- Unplug the TV and either move it or rotate it until you have an unobstructed working area of the back on the monitor.
- Remove all the screws on the back of the TV so that we can get to the actual plugs behind the plastic cover. I can corroborate the poster's remarks when I say that you must not force the back cover off. If it doesn't just poo off then you still have a screw somewhere.
- Before you touch anything on the inside of the TV, touch something metallic so that you can discharge an static electricity. i have seen many pieces of electronics become paper weights because of that little spark.Once the back cover is off, gently push all AV terminals back into the board with your hand.
- Turn the TV back on and check to see if the lines appear. Jiggle the HDMI cord to see if you can get it to create the lines. If not, then you have fixed the problem.
- Put the cover back on and pat yourself on the back.
Pass it around!