If this unit has a prior history I'd like to read about it. The ones I encountered actually had an prior issue where it would turn off and on then finally stay on. The owners were unaware this was a bad sign. They didn't know that using it could result in more boards being damaged and a higher repair bills.

So, please unplug it until it can be serviced. Also, check this list -> http://www.samsung.com/us/capacitorsettlement/

Just because it's on the list does not mean it's that issue. The tech has to check it out.
Bob