It sounds like you are describing a holding screen for example if you had pressed an HDMI source with nothing plugged in, to check this press the Input or Source button on your remote.
This should list a number of sources, and you need to select the option for "Air" should you have a terrestrial cable plugged directly into the TV, if your using a Sky or Digital box you should select the HDMI source the box is connected to.
If this does work the next step would be to perform a factory reset, in order to talk you through this could you advise of the model number of your Hitcahi Tv.
Right we need to get you to perform a factory reset, an interactive guide showing you what to do can be found here.
In essence press menu on the remote, navigate to Install\Tune which is shown on screen, then select First Time Install, Confirm you wish to reset the TV, then it should reset and load up normally.
If this fails, you will need to take the TV to a service centre, as it would indicate a main board failure, should the factory reset above no work let me know of your address and I can find a suitable service centre you can use near by.