Mirai 32" LCD TV flashing black screen

Hi,

I have a Mirai 32" LCD TV. After it has been on for approx. 2 hrs the screen flashes black before staying black. The green light stays on the whole time. This happens regardless of whether I am watching satellite through the scart lead or a DVD through the HDMI cable. If I turn the TV off and wait a minute and then turn it on again, it will work for approx. 10mins before the same thing happens again. Anyone any ideas on what the problem is here or if it is fixable?

From reading the little amount of information I can find on the internet I have changed the picture setting to "movie" which makes the picture darker and it has been running for about 30mins now since it started the flashing black screen. This will only be a temporary fix as there is obviously still an underlying problem that is only likely to get worse.
This problem only started last night....any help or information on the issue would be much appreciated

Thanks

G