So I was there yesterday because my IP4 has been becoming unresponsive during or right after phone calls. I was there yesterday and the tech did a hard restore, whatever that is and told me to come back if the issue doesn't resolve. This morning I was on the phone and during the call the screen went dark but I didn't lose my call. It stayed dark and unresponsive for about 5 mins. This is my third trip there. On my first trip it was because my IP4 had a brownish bar visible on the display that did not go away after over a week... you know the glue issue? The genius couldn't see it. I noticed the same brownish bar on all the floor models as well so, I guess that is something I am going to have to live with but not this shutdown problem. I hope I get one from a better batch.