If this is in the USA, register the set at samsung.com and then call it in.
I have a 51" Samsung Smart TV purchased a little less than a year ago. Model #PN51E550D1FXZA. Everything worked fine out of the box, connected to WiFi, etc. Sometime in July 13, the TV started shutting off on its own, and then turning back on after a couple of seconds. Sometimes it would repeat this several times, other times, it would happen just once. Then, realized that the TV was no longer connected to the internet. Checked network settings, and the TV does not recognize our network, or any other networks in range. Reset router and modem multiple times, no change. All other devices are connected. Manually ran the firmware update today via USB with no change to internet connectivity. Please advise.