Error Code

Fixing HP 79 Service Error

The 79 Service Error on HP LaserJet printers occurs when the printer receives a corrupted print job or a command it cannot process. The printer firmware crashes and reboots in a loop, displaying this error.

Step 1: Clear the Print Queue on All Devices

The printer is stuck in a loop because it keeps trying to process the same corrupted file over the network.

Turn the printer off.
On the computer that sent the print job, open Printers & scanners.
Select your HP printer and click Open queue.
Right-click any pending documents and select Cancel.
Crucial: If the printer is on a network, ensure all computers connected to it have their print queues cleared.

Step 2: Disconnect from the Network

With the printer still off, unplug the Ethernet cable (if used).
If the printer is connected via Wi-Fi, turn off your router temporarily.
Turn the printer on.
If the printer boots to the normal “Ready” screen without the 79 error, it confirms that a corrupt job was coming over the network.
Turn the router back on or reconnect the Ethernet cable.

Step 3: Disable IPv6

If the error continues occurring randomly on a network, the IPv6 protocol often conflicts with HP LaserJet firmware.

On the printer’s control panel, navigate to the Network Setup menu.
Select IPv6 Configuration.
Change the setting from On to Off.
Restart the printer.