HP 4620 - Manual (Page 141)

• Do not force paper too far forward in the input tray.
• Use paper types that are recommended for the printer. For more information, see
Media specifications.
• If the printer is about to run out of paper, allow the printer to run out of paper first,
and then add paper. Do not try to add paper when the printer is trying to pick up a
sheet.
• Make sure that the printer is clean. For more information, see Maintain the printer.
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