I have exactly the same problem with an iphone 6 plus. Replaced a working cracked screen with a new one (used my camera, homebutton and backplate. When I switched it on the new one had a backlight but nothing on the screen except a bit of light. Put the old screen back on and it works ok. Returned the screen and bought another one from a different supplier with the camera and backplate already fitted and exactly the same issue! Is this coincidence I’ve had two defective screens with the same problem or is it something else?
Make sure you pry the battery connector off from the right hand side as shown in the picture. Theres a delicate component on the logicboard near the battery connector called a Mosfet which is linked to the battery charging software. If you knock it off accidently you’ll loose battery charging and the phone will boot loop and youll need to have it re-soldered back on.
Make sure you pry the battery connector off from the right hand side as shown in the picture. Theres a delicate component on the logicboard near the battery connector called a Mosfet which is linked to the battery charging software. If you knock it off accidently you’ll loose battery charging and the phone will boot loop and youll need to have it re-soldered back on.