http://uk.answers.yahoo.com/ques ... 110621013953AA5psj7
I rang the sony helpline in the end. The problem was that the TV was set to automatically recognise when a laptop is connected. It was not doing this so you had to go to Settings>ExternalInput>AVPreset>Then set the PC Input to Always rather than Auto. That way it is always set to discover your laptop when you connect it.