This television is experiencing a component breakdown. This is probably from a overheating problem. The break down component is probably a capacitor. The component has lot its ability to control it operations.When it fails the television goes into the protection mode. This allows the component to cool down and to heal itself temporarily. This will not last and you will need to have the television test for faulty components.The repair of this should not be too expensive.You should call a service center and ask for a estimate of the repair cost before taking it in to be repaired. You may be able to do the repair if you have some experience working with electronic test equipment and tools. you will need a large work space, screw drivers, soldering iron and some test equipment.A digital multimeter will be needed to test some components, if a solid state component has become faulty. Usually a diode or transistor.The repair will require good soldering techniques.you must visually inspect the circuit boards and replace faulty components as found. Remember these are high temperature components and need to be replaced with the same high temperature ratings. You may want to try cooling the television with a constant cool air flow to save it from further damaged. I hope this information helps you with your problem.