I would suggest you to a factory reset, go to the Menu, select support then Factory Reset.
It sounds like the settings have become currupt.
Please let me know how you get on after performing the factory reset, if you need further guidance on performing the reset let me know
No problem Eamon it just means you have a slightly different software release running on your TV.
Set the source to terrestrial TV (not HDMI), and ensure no other menus are open.
Then goto Menu > Support > Self Diagnosis > Reset
If prompted for a PIN use 0000 (which is the default unless you have changed it)
If your having issues access self diagnosis still, disabled game mode by going to Menu > System > General > Game Mode
Please let me know how you get on.
Most likely cause is the software become confused \ corrupt, maybe you plugged in the HDMI cables when the TV was switched on and it couldnt correctly detect the devices, its the joy of TV's now having computers basically controlling them.
It may be worth checking your TV has the latest firmware version now the TV has access to the internet via WIFI, there should be an option under the Support menu to check for updates.
Glad your working again, so I may resolve this case can you please rate the service received.