OfficeJet Pro 6978 won't print black

[DonStang]

My black ink cartidge is 90% full but it won't print black. It will print color.  I reset the black cartridge but no success.  Does anybody have a suggestion?  Thanks, Don

[Jeet_singh]

@DonStang,

Thank you for posting your query on HP Community,

Are you using genuine HP Ink cartridges or refilled ink cartridges.

Let's try these steps here: 

Please make sure that the printer is connected directly to the wall outlet and not to the surge protector.

Remove all the ink cartridges and then try to perform a hard reset on the printer.

With the printer turned on, disconnect the power cord from the rear of the printer and also unplug the power cord from the wall outlet.

Remove USB cable, if present.

Wait for 2-3 minutes, press and hold the power button on your printer for about 30 seconds to remove any additional charge.

Now plug back the power cable straight to a wall outlet without any surge protector or an extension cord and then plug back the power cord to the printer.

Turn on the printer and wait till warm-up period finishes and the printer is idle.

Now insert the ink cartridges and then try to print a test page and check if it works.

If the issue persists, I would suggest here is to Print a Print Quality Diagnostic report, and then evaluate the results.

1. Load plain white paper in the input tray.

2. From the printer control panel, open the Setup  menu.

3. Open the Reports or Tools menu.

4. Touch Print Quality Report.

Evaluate the report for any defects. 

• If there are defects found, try the steps mentioned in this document.
• You may also try to clean the ink cartridge contacts and Refer to solution# 3, 4, and 5 from this document. 

Let me know how it goes for further assistance. 

That said, If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution and Kudos buttons, that'll help us and others see that we've got the answers!

Have a great day!

[DonStang]

Thank you.  My printer is working but I don't know why.  I was away for a few days, came back and printed something.  The printer went into it's periodic self-maintenance routine and when it finished it printed my document.  

I very much appreciate your reply.  

[Jeet_singh]

@DonStang,

I'm glad you got this issue sorted out.

Do visit our HP Forums and drop us a message anytime you need help

Thank you 😀