This is fairly common on LCD and plasma screens. It can be caused by a number of different things; the most common is the connection to the edge of the LCD. If you search YouTube you can find videos that show how to fix. It’s fiddly to get the TV apart, you’ll need plenty of room, and discipline in labelling the screws so that you can put them all back in to the same places.[br]
Be very careful when repairing; you’ll have to run the TV out of its case with exposed connections. I can’t remember if your model uses a cold-cathode high voltage backlight or not; if it does there could be 1000V or more exposed at the edge of the screen.