I accidently dropped my phone and soon did a replacement with an aftermarket screen which looks just like the original. All features work on the phone as far as I know. The only problem I'm having is with GPS/Google Maps. It cannot keep a track of my location whilst moving, but it able to pick up my location prior to navigating, as in, it knows where I am. Of course, it was working before the screen replacement. I don't know whether there is a separate GPS unit, but seeing as it can pick up my location, I suspect it's not disconnected physically. What can I do to properly test this, or rectify the problem?