Black Screen after screen replacement

Went through some of the questions previously asked for the same problem/device. I've replaced several parts over the years on my iPhones without trouble, but recently when I tried to do a screen replacement, when I turn the phone on, I can see that the LCD lights up, but I only get a black screen. I can also tell that the TouchID is working, as my phone buzzes to let me know that I need to input my passcode upon rebooting the phone.

Since this is commonly asked, yes, I powered my phone down and disconnected my battery each time I went into my phone. I also brought the touchID, camera/speaker, and metal plate from my original screen over. I then went back to my original screen to see if maybe I had gotten a bad part, but my original screen is also only showing black. I'll need to wait until I can get home to put the circuitry under a microscope, but in the meantime, any suggestions or ideas as to what may be causing the problem? Just to reiterate, the screen does turn on, it just displays black. Thanks.