Long screw damage problem

Hi, i have same problem.the screw which i took from stand off hole cant be fitted again(the screw which is in top left)...so i assembled it without that screw..now itunes detects it and even show battery percentage but still black screen,receiving calls would vibrate with no sound,,silent/general toggle switch doesn't change state...pleases help

There were no visible damage in motherboard...even the rubber casing on small components have not been removed...so i hope there were no damage in hardware externally...but when i look inside left bottom screw tracks are visible but they doesn't seem to be damaged...is this possibly be a long screw damage...because my iphone still receive calls ...only display and touchscreen is not working....im planing to swap display by this weak end and ill update status...so that anyone facing the symptoms will be helped....will a long screw damage will result in above symptoms?