My radio recently failed, and I did several head unit swaps during troubleshooting, etc, so I pulled off that faceplate many times. But I left the (2?) screen harness attached and just rotated the faceplate to rest on the upper dash. I did disconnect all the others, of course. A few times during this process, the faceplate backlight stopped working, but would often work the next time I messed with it. My theory was that one of the wires/pins didn't seat perfectly after after messing with it, so I made sure to push the wires into the connectors next time I did it. Everything works fine now. So maybe you pulled one wire on the screen connectors just out slightly? Try to press the wires into the connector individually (or look for one that isn't fully seated). Did you take out the head unit too? If so, do the same to those harnesses, as the head unit is what tells the screen to turn on.