Philips 28PW6332/05 TV Fault

[sbanks]

Hi,
my television has started to morph the screen into a "green" hour-glass
shape on occasion and make a buzzing sound. This has been intermittent and on occasion has also switched the TV off then on and then back off again.

Any ideas?

Is it expensive to fix?

I am not that technical so I am just looking for a idea whether it is on its way out or it can be easily fixed. Also its an excuse to get a new Plasma or LCD