Many perfectly serviceable Samsung "smart" flat-screen TVs of all sizes are being abandoned and thrown into land-fill because of a simple problem. This might well apply to other brands too; we shall see.
Should your Samsung set start to exhibit the widely-discussed and annoying "shutting-down" behaviour, it might of course, although relatively rarely, be on account of an actual hardware failure, although please first consider this.
When the set tries to start up, select "MENU" and go to the network options and disable some of the "sinister things" there (sorry, i shall have to go back to identify what these are exactly), although it is basically trying to "fone home" and, unless it already has its own credentials established on your home network, this will fail. By disabling the network stuff, it will be free to live another day.
These are actually very well-engineered products, although alas this software Achilles' heel might almost be accused of being "planned obsolescence" by the cynical. Acknowledged, the techno-savvy would have lodged their TVs on their LANs...