I'm very sorry for any inconvenience this may have caused you. Unfortunately, this sounds like it may need servicing. Here's the thread where you can get details on setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
I have Samsung UN55C7000 3d tv. Up to last December I had Dish Network Box connected through HDMI cable to. Everything was going great. This year I changed my tv provider to Comcast and I have some problems. When I connect Cable box (digital or HD I tried both) my Samsung video apps are freezing. Movies from my PC connected through network cable are freezing too. It's really often showing the message "Preparing to play". As soon I disconnect coaxial cable from outlet or the box, everything going smooth again. Comcast Tech. said that it's some returning voltage from tv when cables are connected. I thought it was because of coaxial cable but I changed digital box to HD one with HDMI cable and it didn't solve my problem. Samsung Customer Service said it is Comcast issue, but why I have problems with movies from PC connected through network cable. It looks like tv cannot handle that many signals (BD player, TV, PlayStation, network, PC). Any ideas what is really wrong and if I can solve that problem?