Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It would be from the backside, with the ribbon closer to the main board. That was the ribbon causing the horizontal lines on my set.

As for cleaning, all I used was a microfiber cloth and a good hard rub on both ends of the ribbon. Air was used on the connectors, which had plenty of dust.

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Add me to the list with the exact SAME problem! After google brought me to this post, I decided to open and poke around inside my TV as well. After an hour, I found that if I would move one of the four ribbons (far right) that goes from the t con to the panel, the lines would disappear but colored vertical lines would show instead. So I took out the ribbon, cleaned both ends, cleaned the connector on the t con, and switched it with the ribbon on the far left. BAM! Horizontal lines gone. Maybe the ribbons are faulty?
...