This can often be caused by a lamp that is starting to go bad. as the light gets older it will draw more than it should. The safety circuit in the TV will shut it down when it detects a problem. There could be other parts that are no longer within the needed specifications but I suspect that replacing the lamp will correct the problem.
If replacing the lamp does not correct the problem these sets are assembled using the wave soldering process they are known for having cold solder connections. The safety circuitry shuts the TV set down when it detects a problem.
This model of TV has over 3,000 parts which include millions of transistors inside the integrated circuits. The capacitors will change value, leak and become defective. Resistors will change value and burn. Integrated circuits and transistors can go bad. This can cause other components to become defective, which can have a domino effect and cause other parts to fail. Replacing one defective part may make the TV operate for a short time but the part will fail again since if the parts that caused the failure to begin with are not replaced.
The only way to know for sure what is causing the problem, which parts are no longer within factory specs and for proper repair, all the electronics must be diagnosed by someone with the correct electronic test equipment and the skills to use the test equipment.
I wish I could tell you there was a quick fix or button to push that would fix the TV but that is not the case or the solution needed to get the TV operating correctly.
If you wish to repair it yourself what type of electronic training do you have?
What type of TV test equipment do you own?
Do you own and know how to operate an oscilloscope?
If you decide this is not something that you can do, I expect this repair will be about $150 to $350, depending on how many parts are found to be out of factory specifications. If the problem is a bad circuit board and if the board can be repaired or has to be replaced, a small TV repair shop often charges less for the repair than a large electronics repair facility.
Should you require further clarification, please don't hesitate to ask.