My 40pfl5605h/12 tv is restarting continuously. It shows movie 2 or 3 seconds and the shutdown. Remote doesn't work (I can't get homescreen).

If I let tv without power for two weeks and then turn it on, it works great(also remote control works ). But when I turn it off and try to turn it on again, it will restarting continuously and never stays on.

I updated the latest software, but no help...

Maybe broken powersource? Or software problem??