If the spacing between the top and bottom sections of the front and back Side guides is inconsistent, the paper may not be able to be fed properly. If this is the case, adjust the Side guides so that the spacing between the top and bottom sections is uniform.
For details about the procedure, refer to Making Minor Adjustments to the Side guides of Paper Feeder Unit PF-602m or Making Minor Adjustments to the Side guides of Paper Feed Unit PF-707m.