Chosen Solution
I have an iPhone 5, and I accidentally removed some of the black coating on the back of the home button, using rubbing alcohol and a Q-Tip. What is that stuff?
When I powered the phone on again, I found the home button wasn’t working at all, and I thought I would have to replace it; then I simply rotated the home button 180 degrees and powered the phone on again, and this time, it worked just fine. Can anyone tell me what that black coating is, and what its function might be? Thanks.
The black coating is most likely what keeps your home button in place, making sure when you press it actually hits the button that triggers the startup instead of just missing it, not triggering the button.
