These units auto update.
There is a possible underlying hardware problem,
but I've talked to dozens of people today with this same samsung series that is having the same issue, and all were coming up after a recent software update this morning/last night. All signs at this point would indicate a defective firmware version.
Myself and several other techs have made samsung aware of the issue and they are working on a patch for it.
Because it is a significant issue and affecting so many, I would expect this to be an immediate release, meaning within the next few days at most.
You can try unplugging the tv for a few minutes then back on to let it auto update,
and beyond that we just need to wait a few days for the next update to release.
If you find the problem continues beyond that, meaning it is not software related, then I can review some other hardware options with you.