aKURA av32720hd?

Hi,
My tv's warrnenty has now ended and has broken. It has done it 3 times during the 12months warranty period.

The picture just goes completley and gives coloured horizontal lines, this can sometimes go away with a light knock to the top of the unit, other times i have to turn it off for 20 mins and sometimes the picture comes back.

Any ideas on the cause of problem. I have contact Akura and advised i should still be under warranty due to it breaking again everyime following the repair but no joy at yet.

You advice?

Many Thanks