Facing TV Problems? Ask a TV Technician.
It does sound like it might be faulty.... But first just make sure it is on the right input... Can you coonect a DVD player, then go to that input and get a picture?
Then the TV itself is working but there may be a problem with the freeview tuner... Go through the tuning setup again and get the channels loaded, make sure you follow through and Save the settings otherwise when you turn off the TV they get wiped and you have to reload... If this happens even after you save then the TV is not saving the settings and has a fault and should be replaced under warranty...