HP LaserJet M4349 Multifunction Printer series - Manual (Page 205)

4. Slide the tray completely out of the device, and remove any damaged media from the tray.
5. Slide the tray into the device.
6. If a jam message persists, jammed media is still in the device. Look for the jam in another location.
Clear jams from the optional duplexer
If a jam occurs during a duplex printing job, use this procedure to check for the jam and to clear it.
1. Remove the output bin (or remove the stapler/stacker or the mailbox).
2. Remove the optional duplexer.
ENWW Clear jams 191