HP Officejet J5740 All-in-One Printer - Manual (Page 165)

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 print carriage has stalled.
Solution: Turn the HP All-in-One off, remove any objects that are blocking the print
carriage (including any packing materials), and then turn the HP All-in-One on again.
Cause: The computer is not communicating with the HP All-in-One.
Print troubleshooting 163