You did get a good TV but all of them are at the mercy of your powerline.What is UPS? I just had it on WiFi. This problem with Samsung is common I spent around 400.00 for a smart TV that lasted a little over 3 years. The LEDs Burned out. The problem is they are in series. So if one or two burnout then the rest won't work. The T Con board was still good. And you know the power supply still works if you get sound. My old CRT TV that I replaced was over 10 yrs old and had a great picture but It was so big I thought I was getting something great to hang on the wall and free up some space.
Old TV's had lots of parts that could take power hits because they were designed to tolerate them. New electronics could do the same but they are designed cheaply with the idea that a newer one will replace it in a few years.
Buy a good Uninterruptible Power Supply and put it on your cheap TV and it's support devices. You will be amazed at how long the TV will last. Make sure you put the signal feed through the UPS as well.