Dropped my two week old Nexus 5 on the ground... if you look at it, everything looks fine. Apps work, wi-fi works BUT I can no longer pick up a mobile network. It just shows a black signal (black triangle where the signal bars would be). I try to go into Settings > Mobile Networks > Network Operators to Search Networks or Choose automatically and it just searches but can't find anything. I can't figure it out. Everything seems to be OK but I can't get a mobile network. I took it to a cell repair place but they couldn't figure it out after opening it up. Any ideas?