I haven't used my Roku (ROKU 3) in a while and I recently plugged it up in my office on a Panasonic TV. It worked fine and there were no issues. Today, it loaded got me to the opening screen and the screen will start flashing/blinking very quickly. I am unable to do anything and get to a main menu. What do I do?? I've seen posts about changing the HDMI ports and the cables and I've done that and it still loads and does the same thing. I just want to be able to watch TV in my office from time to time. Please help.