Having same problem with canon MF5770. Scanning (e.g. blank A4 page) from the ADF has grey lines while copying from the ADF prints a white page), meaning that it's not a cleaning problem (or scanning uses some other mechanism than when reading the page for printing which wouldn't be logical). Of course scanning from glass works too. Replacing drivers can't do since latest seem to be 2015 and are installed. How to fix this?