234 Paper Jam - Check Duplex
There is a paper jam in the duplex unit, but the printer cannot identify the location.
1. Remove Tray 1, and then depress the lever in the duplex paper path area..
CAUTION: The inside of the printer might be hot. To reduce the risk of injury from a hot component, allow the surface to cool before touching it.
2. Remove any jammed paper.
3. Replace Tray 1.