Canon DADF-AV1 Service Manual page 78

2. Pull out the set paper.
Pull out the paper in the direction of the arrow to check that slight resistance is felt.
3. Check the front-left height of the DADF.
Set paper against the protrusion in such a manner that the sheet is nearly hidden, and then close the DADF.
CAUTION:
Set paper so that it does not reach the document reader.
Paper
72
5. Adjustment