If there is only an issue with the ADF, there is only one component different than when scanning from the Glass, it is the narrow strip (CVT) glass on the left, take a look and see what is on it right here.
I am having an issue with my xerox when I make copies from the feed tray.
I will put some pages into the feed tray and when my copies come out it looks as though it was scanned on the glass and it is askew by 1/2 inch. It has a line at the top of the page that looks like I put a page on the glass scanner and did not push the page all the way to the tope.
Please advise
Julian