How to Replace a HP Printer Carriage Belt

Unplug the power cord from the printer and disconnect any cables attached to computers. Wait fifteen minutes to make sure the printer is completely cooled down before proceeding.
Remove the computer's top cover. On some model this requires finding plastic tabs to snap the cover off. Other models have a hinged access door that simply lifts up.
Locate the printer's carriage belt. Find the clips that hold the carriage in place. Make note of the type of screws holding the clips in place; some printers use Phillips screws and others use Torx screws.
Remove the screws holding the printer carriage belt in place. Be careful not to drop any of the screws into the printer as they may be hard to locate.
Unthread the carriage belt and replace it with the new carriage belt. Be careful to place the new carriage belt through the clips in the same way the old belt was.
Return all the screws to their original spots, making sure to tighten them so they will not come loose. Remember that the printer carriage belt moves constantly during operation.
Replace the printer's cover. Plug the electrical cord back in and reconnect the printer to the computer.