brand new tv, just out the box today. The tv has been on about 3hours and this appears.
what do I do?
Hi @Jo chew welcome to the Samsung Community 
Whilst it may not made a huge difference can you name your model. Is the number appearing on all channels/sources? Being a new Tv you should have the lastest firmware.
An idea is to switch off the Tv at the mains whilst the screen is asctive for around 30 seconds, do not power off with the Remote and then reconnect. This problem has been reported before but it is a rare error. If this does not solve it try a Factory Reset.
