Problem: vertical black lines when faxing or copying using the automatic document feeder (ADF) but does not exhibit this problem when using the flatbed scanner. This particular problem applies only to a multifunction machine with both flatbed and ADF capability. The solution might be as simple as cleaning the narrow strip of glass that the ADF unit passes the document over. Most cleaning efforts can be done with a slightly damp cloth. If the glass has whiteout on it, you will need to break up the whiteout with your finger nail. If you try to use something other than your finger nail you may actually scratch the glass.