When switching T.V on, the sound works but without...

Question

In the morning when the TV is switched on. the sound comes on but without a picture and the problem persist even if I press other buttons on the TV remote control.
I have to turn off the TV from the remote control and the wall socket switch and turn them back on for about three or four attempts before the TV operates properly. When I phoned the company as the TV is only eleven months old and still under guarantee I was told that it could be the power supply. I am not sure if this is correct or not.
Any suggestions to this problems is greatly appreciated.Thanking you in advance.Mario