Chosen Solution
I am currently working getting an iPhone repaired. The problem is the display won’t show anything and there is no visible damage to it at all. I have replaced the battery and when I touch the cover of the display cable it is fairly warm. When I plug it in it makes the charging sound but it won’t show up on iTunes. What could be the issue
If it makes a charging sound it is showing signs of life. The first thing you need to do is rule out a faulty screen. If your phone has a passcode you will need to enter it before iTunes will recognise it.