LCD Screen Not functioning Correctly

Hi All looking for some help. Was using my 7d in Auto mode and all of a sudden the LCD screen went blank, no playback, no menu and no info. All of this applies only to the following modes: M, AV, TV & P. The ISO settings will also not change. I am not sure if i have done something or bumped something. I managed to get the menu screen up, cleared all settings, suddenly worked then when i re-applied some of the settings it has gone back to showing nothing again???. Can anyone help? Lens is currently sitting in AF mode.