Narrow color strip across TV screen?

I'm not exactly sure when it started.I came into the living room,and there was a horizontal stripe across the TV screen.you can still see vague colors and most movements,but it looks as if its in a VERY widescreen setup,as the screen itself is 16 in. tall by 20 wide,and the color bar is less than 1/8 of an inch thick.If it helps,its an Emerson EWF2004A.The online manual says to check for interference,but its on cable and the normal TC reception isn't working either.im going to ume it's an internal problem? if it is,how much would you estimate it to be fixed?