My phone screen will not stay on unless I hold it and slightly bend it at the top left corner. When I do that, the screen will sometimes stay on. It was doing this for a few weeks, something I could get by with but quite annoying. Today, however, the screen is not responding at all, however, I can hold the power/volume button and get a vibration for the reset and then click power again to feel another vibration. So the phone is responding, it just won't turn on at all. What parts should I replace to make it work?