if that happen with water damage try to dry it by disassemble it and dry it us the heat gun and assemble it again ,if not it is hard wear damage with one of screen boost coil
Hi at this time the problem is the motherboard water did alot of damage did short with the alot of chaps and lost the software , any way try to download software probably will work
try to conntact the Iphone to ITUNE program and see what the message you have got missing software it will light the light on or maybe you need to restor the Iphone by using thre program any way follow the program step and see
