Chosen Solution
i have an iPhone 5c which has a black screen although the touch still works, i realized this when a alarm rung and i turned it off by the screen, i also looked at another article which suggested a connector on the logic board may be damaged, i have looked and have not found anything that looks damaged or a missing connector or pin
So did this just happen suddenly or following a drop or other impact? As @benjamen50 suggests, it could just be a bad screen that needs to be replaced. You can find one here and the repair guide here. If that doesn’t work, shine a flashlight on the screen to see if there is a dim image. If you can see one, then you likely have a logic board issue, specifically in the backlight driver circuitry. It could be just a blown backlight filter or it could be further upstream. This will require a micro-soldering repair and is not DIY.
