Chosen Solution

I repaired a 6S.It can’t start up any more.But i don’t know what a Problem is.The Computer also can’t recognize it. So i wanna know,if the Battery is total break,is there the possible ,that the Computer can’t read it?Or some others seasons,such as Mainbord? Thank for your help!

If an iPhone doesn’t have battery how do you think the information will go to your Mac?