How can I fix my Mitsubishi big screen tv?

After a recent storm and a power failure my Mitsubishi big screen has audio but no video. Can bring up the menu with the small picture which is working fine. Hooked to a dish and another tv hooked to the dish is working fine so it is not the dish. Get a blue screen and will go from Ant A to Ant. B but not to anything else. Was told to unplug for 15 mins but still does not work. Then after it has been on for a few mins it will turn itself off. Any suggestions, thank you.