There is a possible underlying hardware problem,
but there is currently a known issue with this series tv, thousands of others are having the same issue, and all were coming up after a recent software update that installed automatically 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 want to try speeding it up, you can go into the setup menu and check the "install updates" function periodically.
If you find the problem continues beyond that, meaning it is not software related, then I can review some other hardware options with you.