black screen after screen replaced
I was checking some iPhone 5 screens that I had on a customers iPhone 5s that had a cracked screen. Found a good one. installed all the parts on the new screen. The backlight works and the phone turns on I know because it buzzes. Also if I call the # it rings. Also iTunes see's the phone but I can't set password. But now there is a black screen. I have tried all the button resets from the internet sites. I can see the backlight on the edge of the screen but no video. I have tried several different known good screens but same results. This customer is being patient but I don't know for how long. HELP!