Code 79 is on the screen

[Fancys]

Code 79 is displayed on my printer screen

[Repairatrooper]

If this is an M234, try connecting a network cable instead of a wireless connection and if you can get the printer to ready, go into the menus and disable IPV6 and you should be able to keep using your device. However a total reset might be required and if that is the case post back and someone will escalate your post.

[Heather_Green]

Hi Fancys , could you share the model number of your printer? You should be able to identify it from printer case part. 

If printer model is in the series of HP laserjet MFP M232-237, maybe you could try below steps and see if the issue could be resolved.  

• If possible, use ethernet connection. 
• If printer is connected with wireless, please follow below steps:
1. Turn off the printer, remove the toner cartridge from the printer, and then wait for 30 seconds.
2. Turn on the printer. After ER07 is shown on control panel, insert the toner cartridge.
3. The printer should go back to the Ready mode.
4. Press the Information button  to print the Printer Information Report. The report contains the printer IP address and printer PIN.
5. Open a web browser from computer/mobile device in same network, enter the printer IP address to access the EWS page.
6. Click Networking, and enter ‘admin’ as printer user name, printer PIN as password when pop window showing up. 
7. Go to Advanced at the left panel menu,  uncheck IPv6, and then click Apply at the right-bottom of the page.
8. Close the EWS page. The printer should recover now.
9. If Er79 occurs again, follow step 1-2 to recover the printer.