What is wrong with my TV?

have a 32" Sharp LC-32SD1E TV which has developed a problem. The set will switch on and the picture will be present for a split second and then the screen goes blank. The sound is still present but no picture. If I continue to cycle the TV on and off it will eventually stay on and the picture is good but the number of times I have to switch it on and off before it stays on is growing, at the last count it was around fourteen times before I got a picture. The TV is around 31 months old.