Old 35" CRT TV Only Has Horizontal Line On Screen?

We have had our Mitsubishi 35" CRT TV for over 10 years, and even then it was a refurbished model. It's been working beautifully all these years but today when it was turned on there was nothing but a horizontal line across the screen.

Sound is fine. Moving colors are seen in the line; in fact, it looks like someone took the picture and scrunched it into a line that barely registers on a ruler.

Does anyone know what might be wrong and if so, is it an expensive fix? This TV has had a beautiful picture and is a piece of furniture in itself. In fact, we've felt no need to get a flat panel because the pic on it was huge and colorful.

Any ideas or suggestions would be most appreciated.