samsung picture comes on for a minute then shuts off?

This Samsung is only 2 years old and has been repaired once already because it would not turn on.
For about a week it would come on for a minute or so, we would start to watch a movie then the picture would go out with the sound still working, then the tv would just shut off. tonight there is no picture at all, can see some moving vertical lines then nothing.
The model number is LN32A330J1D