Update HP Printer Apps stops black and blue from printing on two different printers

[AllenLane]

First for OfficeJetPro 6978 (uses cartridges 902); printer was working fine.  Updated printer apps and then the printer immediately stopped printing black and blue ink. 

Did the same printer apps update on a Photosmart 6520 (uses cartridges 564) and it also quit printing black ink on documents, but prints black (other mixed colors) ink of Text on the Print Quality Diagnostic printed page. 

For both printers, changed to new cartridges twice without solving the problem.

[sandytechy20]

@AllenLane

Welcome to the HP support community.

This seems to be a driver issue.

Uninstall the printer driver and reinstall both printers.

Perform root level uninstallation to remove all the printer-related software.

• In Windows, search for and open Programs and Features.
• Select your HP printer.
• Select Uninstall.
• In Windows, search for and open Devices and Printers.
• In the Devices and Printers window look for your HP Printer. If you see it listed, right-click on it and choose "Delete" or "Remove Device.”
• Open up the run command with the "Windows Key + R" key combo.
• Type printui.exe /s and click OK.
• Click on Drivers tab.
• Look for HP Printer driver. If you see it click on it and click Remove at the bottom.
• Select OK.
• Remove all instances of the same.
• Select Apply and OK on the Print Server Properties windows.
• Close Devices and Printers. 
• Restart the PC again.

1)Download and install HP OfficeJet Pro 6978 using HP Smart app

Click here to download the HP Smart app.

Update the printer firmware 

Here are the steps:- Click here

2) Download and install HP Photosmart 6520 printer full feature driver

  Click here to download the driver.

Let me know how it goes.

To thank me for my efforts to help you, please mark my post as an accepted solution so that it benefits several others.

Cheers.