Why my iPhone 6 have black screen but recognize by itunes

"For the 5 screws (or was it 4?) that screw on top of the metal plate cover for the front panel connectors, did you make sure you put them all in the right holes?

Because if you put the longer ones where they shouldn't be, you may have caused damage to the logic board causing this issue."

"Hello,

You need to check a couple things. Really easy and fast.

1. Shine a flashlight in the middle of the screen as you push the power button. If you can see a faint Apple logo, you most likely have backlight issues.

2. Unplug home button and front camera assembly. Just leave the power button, lcd and digitizer plugged in. Now try to turn on, you may have to plug cable in to get it to turn on. If it doesn't, plug in the home button and attempt again by holding home and power simultaneously for 30 seconds. If it still doesn't reply back"

i have a iphone se the screen does not come on but itunes reads it the screen isnt crack from what it seems

I have an iPhone 5s, and it did this yesterday. I didn't do anything to it and it didnt fall, it just went blank but I can still hear it vibrating when a call comes it and all.......help

I have a similar problem. An iPhone 6. The screen went black. Replaced with another. It was ok. Then when refitting went dark but can still see screen. Tried adjusting brightness in settings, it brightened then went darker. Tried another sensor flex but no joy. Any ideas?