I'm very sorry for any inconvenience this may have caused you. Unfortunately, this sounds like it may need servicing. Here's the thread where you can get details on setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
I will get vertical lines across full screen at random times. To remove I can sometimes move wiring at rear connection but returns. Happens weather using a HDMI connection or AV connections.