Samsung SCX-8240NA-CAS - Manual (Page 201)

Troubleshooting_ 201
Clearing original document jams
When an original jams while passing through the duplex automatic
document feeder(DADF), a warning message appears on the display
screen.
To avoid tearing the document, remove the jammed document slowly
and gently.
To prevent document jams, use the scanner glass for thick, thin, or
mixed paper-type originals.
Original paper jam in front of scanner
Click this link to open an animation about clearing a jam.
1. Remove any remaining pages from the DADF.
2. Open the DADF cover.
3. Gently remove the jammed paper from the DADF.
4. Close the DADF cover.