Facing TV Problems? Ask a TV Technician.
Power off the TV, and leave unplugged for 5 minutes.
Connect one device to it, e.g. a DVD player.
Turn the TV back on, select the correct input for the device, and let me know if you get a good picture.
If you do not, then let me know if you can see the on-screen menu ok.
Reply back here and let me know if the power reset works...