Samsung 21" monitors have trouble in 2 areas. Not sure if your "TV" has the same parts in the power supply. In the secondary side of the power supply; there may be some caps 1000uf and around 25 to 30v If I remember correctly. You can google samsung monitors 21" and there are many hits for it. If you have an ESR meter or have something to measure the caps on the secondary side you may find them the fault.
However, there might be a problem with the video board. I've not figure out the trouble with it; either the secondary took the board or it's bad all together by itself. Easy fix if it's the power supply and bad if it's the video board.
Good luck,
kv
Edit: I did find this; it may give you clues. First you have to enjoy the the "Hello Kitty" background.
Second it may be the reason I've not been able to find fault with the video boards.