I have an Hitachi 28 inch widescreen bought in 2000 for £500. The picture is still fine but recently the sound began to go weird. The volume decides to turn itself up to full blast and sometimes doesn't respond to the mute fuction being pressed. Yes I know, rather irritating. Clearly the chip has been infected in some way or another. Anyone had a similar problem? Or is this a unique problem? Is 4-5 years all we should expect from modern appliances or what?