My 50 inch series 5 TCL ROKU TV that I just bought about a month ago suddenly froze and I couldn't even turn it off. Eventually I was able to turn it off, but when I turned it back on a few hours later, everything I tried to play was like a negative and incredibly dark. I tried the method that was suggested by unplugging the TV for about 30 seconds and that worked. Thank you for the suggestion. I hope this episode is not a foreboding of further issues. My older 1080P tv is 12 years old and still going strong but doesn't have near the clarity of this TV.