So I have a standard definition television. Not sure of its size nor the make (i'm sure its on the front of the set but I just haven't bothered looking).

Anyways, its been working perfectly until today. There is this line of light that is creeping from the bottom going up and down, never making it past 1/4 of the screen. Its annoying as hell. Its on all channels, including the video imputs, so I know its the tv itself. I checked each cord thats plugged in and nothing seems to be the cause of it. I'm at a loss.

Any help?