The may be two causes for this behavior:
A. The automatic/Manual feed mode level has been set to Manual. Check the plastic level found on top of the scanner. Make sure it is set to Automatic. This ensures that the separation rollers are engaged.
B. The double-fee prevention roller is not installed. The DF prevention roller is pack separately in the DM 4790 box and needs to be installed. Follow these steps:
- Pull on the scanner cover release and lift the lid to open the scanner.
- Pull up on the double feed prevention roller cover and remove it from the scanner. It is located at the bottom of the ADF tray near where the paper enters the scanner.
- Align the plastic gear end on the right side of the roller with the gears in the roller compartment. Make sure the flat side of the roller tip is aligned properly with the slot in the scanner.
- Carefully insert the gear end into the scanner and angle the roller down into the left side of the compartment.
- Press gently on the metal bar on the left side to lock the roller in place with the black tab in the compartment.
- Place the roller compartment cover in the scanner and lower it into place.
- Press gently on the compartment cover to lock in the scanner. Make sure this cover is fully closed as it may break and cause damage to the scanner if it is not properly in place.
- Close the scanner when you are finished