If you open the back of the TV and locate the main power board, take a close look at all the capacitors. You will find there are 2 of them with dome tops. These need replaced, If you have had it 5 years without this happening before you may consider yourself very very lucky. I've seen this happen well before the tv's 2nd birthday. By the way, to order these caps of ebay should only cost £1 for both at max.
Chris Smith - Cumbria Recycling Ltd, March 2009