A 2 year old Fujitsu PDS4242 has recently developed a strange fault. On start up the picture is fine from all sources. After about 30 mins, what I can only describe as horizontal jitter becomes evident at the bottom of the screen. This gradually gets worse and travels further up the screen until after about an hour and a half it becomes unwatchable. Maybe I'm being paranoid but I'm sure the fans aren't cycling like they used to, they are quietly blowing but I'm sure they used to intermittently 'boost'? I know it's a long shot but does anyone have any first hand experience of this problem? or Does anyone know how overheating affects a screen's picture? Thanks for reading.