I have just purchased a Roku Express device and started to use it about 1-2 weeks ago. It was fine off of purchase and the tv has worked especially well but just starting last night on the 21st of March the tv just randomly shuts off at random intervals. When I turn the tv on with the HMDI cable unplugged from it, it never turns off randomly and same when it is plugged in to the tv but not to the Roku. It only turns the tv off randomly when its plugged into both. I believe that it is the Roku device that is causing the problem but I have no Idea how to check. If someone can give me some instructions or advice on how to fix this that would be amazing.