Missing horizontal lines when printing black ink but not when making black and white copies

[Joel_G7]

My OfficeJet Pro 8710 started printing with horizontal lines in the black ink sections, but the funny thing is that it only does it if I am printing and not copying. In other words, black and white copying works fine.

Recent hardware/software changes: none that I can think of

Troubleshooting Performed: I followed the instructions, including resetting the printer, updating the firmware, putting in a new black ink cartridge, doing diagnostic pages and realignments and nothing has worked. I did not replace printhead because it seems to me that the printhead cannot be the problem if it is copying okay. 

Error Messages: None

Connection: Wifi

The next image shows the problem of the horizontal lines and the second image shows the black and white copy without any horizontal lines:

[Kumar0307]

@Joel_G7, Welcome to the HP Support Community!

Have you tried printing different types of documents like PDF, Word or Webpages and check if the issue persists?

Have you cleaned the printhead thrice(3rd level of cleaning)?

Have you tried printing from any other device and check if the issue persists?

Check for any software updates on MAC

Click here to know how.

Since you have changed the ink cartridge and the issue occurs both in Self test page from printer and the printouts from MAC, it could be an issue with the printhead of the printer.

Keep me posted for further assistance.

[Joel_G7 · Accepted solution]

I just started printing a whole bunch to see if it cleared up and eventually it did. Thanks for responding.

[TEJ1602]

@Joel_G7

That's great! Happy to hear that.  

If you need further assistance feel free to reach out to us.  

Have a great day ahead!