Brother MFC-J2340DW Online User's Manual page 41

8. Make sure the paper length guide (1) touches the edges of the paper.
1
9. Gently adjust the paper width guides (1) to fit the paper.
Make sure the paper guides touch the edges of the paper.
1
10. Make sure the paper is flat in the tray and below the maximum paper mark (1).
Overfilling the paper tray may cause paper jams.
1
11. Replace the tray top cover.
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