I have the same problem on my 50' Panasonic Plasma that was posted by srobsrobusa on 6/8/08 - black lines or black bar appearing 2/3 down on screen. The TV repair guy said it was being transmitted by my cable service. I have since switched to Verizon Fios and still have the problem. It usually happens when the TV has been on for an hour. Now I'm starting to think it's the TV and not the signal.

My parents just went through the same thing. It's the TV. It started the first 3 days they had it. They bought it from Sears. They kept trying to say they did something wrong to it. That they turned it on before they were supposed to. It sat in their living room for 48 hours before anyone turned it on! Sears took months to fix the problem! They were giving them a ton of excuses as to why this happened, yet none of them had to do w/ the TV itself. The line grew bigger and bigger. The line went the whole way across the TV and sometimes even when you would turn it off you could still see where the line was. Then before they knew it they had no sound. They had the TV for 3 months before they finally got it replaced. But they had to do a serious amt. of complaining before anyone would help them! Good Luck w/ it! It's not the cable company. It's the TV. They really must take people for fools. :)

Best Buy's TV service team fixed the problem with my plasma TV. They replaced several parts in the TV. The problem has not returned. Luckly, I was covered by the 3 year warranty which I purchased when I bought the TV.