How to fix service HP Printer Error 79?

If a printer shows a "79 Service Error" (a common error to HP printers) on the LCD display, do the following: Locate the on/off switch on the bottom of the printer. Toggle the switch to the off position and COUNT to 10. Turn the printer on again and the system should be all set.

If a printer shows a "79 Service Error" (a common error to HP printers) on the LCD display, do the following:

1. Locate the on/off switch on the bottom of the printer.
2. Toggle the switch to the off position and COUNT to 10.
3. Turn the printer on again and the system should be all set.

HP Printer Error 79

1. Internet Access
2.     Admin Account (for the computer/s)

Phase #1:

1.     Switch off the HP LaserJet Pro 400 printer.
2.     Check and Remove print jobs from all the computers that have access to your network printer.
3.     In the domain network, check who owns each print job in “See What’s Printing” box.
4.     Log in to each of those accounts and try to remove them from the domain network.
5.     If you still cancel the print jobs via specified accounts, remove and add the HP LaserJet Pro 400 from the list in “Devices and Printers”.

Note: Phase #1 is sufficient for most cases but if the error still persist, proceed to the next steps.

Phase #2:

1.     Switch on the LaserJet Pro 400.
2.     Make sure the printer is connected to the internet. You should have an Ethernet cable running from the device to your switch or router or modem.
3.     On the M401dn control panel/screen, tap the “Network” icon.
4.     Check the IP address on the printer. If it displays 192.168.XXX.XXX, it means you are connected to your home network. Otherwise, check this guide if you are getting something like 169.XXX.XXX.XX.
5.     Go back to the home screen and tap the “Settings” icon.
6.     Select LaserJet Update and check for firmware updates and make sure to get the latest.
7.     Continue by selecting the update. Then, download and install.