HP LaserJet 4000, 4000 T, 4000 N, and 4000 TN Printers - Quick Reference Guide

EN Paper Jams - 18
Do not use paper that has already been used in a printer or
copier. (Do not print on both sides of envelopes,
transparencies, or labels.)
Check that the power supplied to the printer is steady, and
meets printer specifications.
Clean the printer.
Perform routine printer maintenance. Order the Printer
Maintenance Kit. See the user’s guide for the printer.
Solving Repeated Paper Jams (continued)