My Samsung tablet 4 is stuck on the logo screen and it won't turn off.I turned it off this morning because it was being slow and when it turned back on, it got stuck on the logo screen. I turn it off and then it turns itself back on, starting up again and showing me the logos but it keeps getting stuck on the Nook logo.The things is that it hasn't been charging since it started doing this too. What should I do!? Should I wait for it to run out of battery? I have tried the power off and volume down/up strategy, but nothing has worked.