Facing TV Problems? Ask a TV Technician.
Hello and sorry you're having problems. Offhand this is a faulty Mainboard in the TV- which is replaceable, and something you can generally do yourself if you're comfortable removing the back of the TV. The Mainboard provides the turn on command to the TV, and will cause cycling like this which requires unplugging the set to stop it.
However it's worth it to try a hard reset, as sometimes the processor in the TV can simply have locked up.
The first thing you would try, is disconnect the set from power, then press and hold the power button on the TV itself (not the remote), for 10 seconds and release. Then plug the set back in, and also check that the power cord is connected tight at the TV as well. Press power once, and see if the set powers up normally. Try this procedure up to 3 times, and please let me know what happens.
Let em know when you're able to see my reply.