My smamsung lcd tv has thick horizontal lines across screen that move upward, any ideas?

You have what we call 60 Cycle Hum Bar. You also might have audio hum too. The problem is a grounding issue either coming from the source such as a Cable Box or a Sat box. More often this occurs with cable boxes. First unplug the source box from the tv completely. You will find that the Lines have disappeared. Next connect a Coax cable coming from the wall bypassing the Box to the RF input on the tv. If you still have the Lines, then the problem is with the Cable signal not being correctly grounded and you need to call the Cable co.. The Cable box can also be causing this as well. If all of this does not work then try using another set of Component cables as they can cause the same issue.