Both Front and Rear Camera not working after screen replacement!

Alright guys. So I replaced a customers iPhone 7 Plus screen yesterday, pretty standard stuff. Took all the parts off his old screen and transferred them to a new screen. Seemed to be fine so I checked him out. He comes back into the store 5 minutes later and neither his front or back cameras show anything. Just black. The camera app fully loads and everything, just black. No errors or anything from the app. So I don't know what the problem could be, seeing as how they're in two completely separate parts of the logic board. Any help would be appreciated!! Thanks!