HP Officejet J5740 All-in-One Printer - Manual (Page 147)

5. Slide the paper-width guide inward until it stops at the edge of the paper.
Do not overload the input tray; make sure the stack of paper fits within the input
tray and is no higher than the top of the paper-width guide.
6. Replace the output tray.
7. Flip the tray extender up toward you.
NOTE: When you use legal-size paper, leave the tray extender closed.
Cause: The original might have been loaded incorrectly into the sending fax
machine.
Solution: Ask the sender to check that the fax was sent correctly.
Cause: More than one type of paper is loaded in the input tray.
Print quality troubleshooting 145