Chosen Solution
I have just fixed an iPhone 6’s screen for a Cutomer. And the screen is black. It works because iTunes recognises it. Tried the old screen and also another screen and none of the 3 screens work.
You may have blown the backlight circuit on the logic board. To be certain, shine a bright light on the screen after you connect it to an iTunes enabled computer. If you see a dim image, then the backlight circuit is damaged. This will require a micro-soldering repair.
is there image and no backlight ?
Take Diode Mode readings of the FPC’s and compare to 1st image, check Filters for continuity…For backlight, pay attention to image 2, and for image, you can start with 3 - 5, but may also find LCM Reset, Photon alive, etc while looking through diode mode readings if off…
sounds like you blew the backlight 99% of the time that happens because the battery was not disconnected during the repair
