iPhone restarts after screen goes black

Unfortunately, we don't have schematics for the 11 Pro, so it's hard to be sure what the I2C3 bus controls. However, on the 11 Pro Max, which we do have diagrams for, that bus goes to the camera power management chip and the touch screen controller.

The part that's wired to the camera PMU is all onboard the motherboard, so if that's causing the problem you're looking at board level repairs. However, if it's the touch controller part that's the issue, then replacing the screen would be the most promising way to fix it.

Alisha, ( @flannelist ), in your experience, how similar are the I2C busses between regular iPhones and Max or Plus iPhones? Is it reasonable to assume a good probability that the 11 Pro uses the same bus going to the touch screen as the 11 Pro Max?

Thanks Alisha, I knew I could count on you for some good information!

So Nefanda, the two of us are some of the top experts on iPhones here on this forum, and we're in agreement that your best bet for fixing your phone is to replace the screen. While we can't guarantee absolutely this will solve the problem, it's your best and cheapest chance in our opinion.