DIAGNOSIS A paper sensor flag is stuck or a tiny paper fragment is obstructing a sensor. Common locations are the rear duplex path or the registration area.
FIX Perform a full clearance check. Power off. Open the rear cover. Check the duplex path for fragments. Open the front cover. Remove the toner and drum unit. Visually inspect the paper path from tray to rear exit. Look for a small torn corner. Manually move all orange sensor flags you can see, ensuring they spring back. Reinstall all components. Power on.
IF THAT DIDN'T WORK The paper jam detection may be erroneous due to a faulty sensor. Print the error history report. Navigate: Menu > Reports > Error History. If it shows repeated jams at the same location (e.g., 'Rear Side'), that sensor may need replacement.
HEADS UP Always remove jammed paper by pulling in the direction of paper travel. Pulling backwards can tear the paper and leave fragments.