hi, here is what can be done to rectify the problem..iphone like any other phone is fragile....one need to be careful with it always....since your iphone dropped the possible problem that arrive from it is that..your iphone must have loose which cause no service problem..since sometimes the sevice we show up and later dissapear..look for a tech that knows well about the iphone and let them loose the iphone to the back side and tighten up any loose part....am sure this would work.