Bent Iphone 5s

Well,hi my 5s got bent,i bring it to the mobile store because it have warranty but they said that it cant be fixed,but before i take it there when i plugged it in the computer it showed no sign it was dead,the phone wont communicate with the PC,but now after i took it from them,i just connected it and it showed (DFU mode) {the phone is not working it wont power on} What could be the problem anyone? is it possible that the motherboard is dead?,should i bring to some tehnician or try something at home,any suggestion?