Forgot to say...
The TV is connected to Sky box via HDMI and to Wii console. And it did the same with both.
I've got a Samsung LED backlit TV, just over 2 years old. Recently after about 5 to 10 minutes of being switched on it changes the picture with a lot of off colours and patches. You can still recognize the faces on the TV (sort of) but nothing else.
I've tried to update its firmware but it didn't let me "no file to upgrade".
Does anyone know what the problem is?
Thanks a lot.