Officejet Pro 6978 fails to print docs (direct USB connection)

[BartSm]

Installed Officejet Pro 6978 to a Windows 10 PC using a direct USB connection. It worked fine for a while. Added a USB sharing switch to allow 2 pc's to share the printer. It worked fine for a while, then printing stopped working for one PC, but not the other. Simplified configuration to direct USB connection (i.e. NOT using the USB switch) to troubleshoot & isolate problem.

- Uninstalled all software for this printer

- Installed latest FULL software for this printer from HP Support, as well as LATEST firmware, and basic printer driver

- Windows print queue window shows print jobs going through queue and flushing out after "printed". Nothing prints and the printer appears to be in ready state as if nothing happened.

- HP Print & Scan Doctor show everything green and check marked as if nothing is wrong. Printing a test from that program to the "PRINTER INTERNAL TEST AND STATUS" report programs works fine. Printing using the Windows "Print Test Page" shows the print job passing through the print queue as if printed, but nothing happens on the printer. No error messages, no abnormal status information returned. HP Print & Scan Doctor also reads and reports information returned from the printer (e.g. Printer Name, Serial Number, Ink Levels, etc.)

- Have tried fully removing and reinstalling the printer software and drivers multiple times, with reboots in between. Nothing resolves the problem.

- Have created a new user account with Administrator-level privileges. All problems replicate in this account, same as before.

- Substituted another known good USB printer cable. All problems replicate as before without resolution.

- Obviously the PC can initiate and communicate a print request to the printer if it can recognize the printer for driver & software installation, and tell it to print a page from its internal status and report functions and produce beautifully printed output on demand. So, why is normal Windows 10 printing not coming out of the printer? And more importantly, how do we resolve this problem?

[TEJ1602]

@BartSm, Welcome to HP Support Community!

Thank you for a detailed report on the issue and the steps already taken in order to resolve it-

I would suggest you try the Windows built-in drivers. Follow the steps below:

•    Go to Control Panel - Devices and printers - Click on "Add printer" and follow the on-screen instructions.

•    When the page prompts for the drivers, select "Windows update". The driver list will be updated.

•    Click HP, Hewlett Packard, or Hewlett-Packard in the Manufacturer pane, and then click the name of your printer in the Printers pane.

Refer to this document HP Printers - Installing and Using the Windows Built-in Print Driver for help

Try printing.

Hope this helps! Keep me posted. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

[BartSm]

Already tried letting Windows Update try to update the driver. That also did not work. The second PC that had formerly worked with the printer now exhibits the same problem and is unable to print. Pattern of behavior is the same. Print job passes through the print queue in normal fashion with no output from printer and no error conditions reported by the printer or Windows. Is this possibly a case of windows "automagically" picking or changing the driver despite all efforts to install the correct driver? In my long IT career I recall instances where the wrong driver file has to be hunted down and manually deleted in order to get Windows to stop using it. Is that perhaps the case here? If so, how can we determine the correct driver file name, and identify the name and location of the "defective or deviant" driver file for removal. Or, other solution? Please help. All efforts are appreciated. (I've also already run the Windows System File Checker (SFC /scannow) and the problem persists as described.)

[BartSm]

Already tried letting Windows Update try to update the driver. That also did not work. The second PC that had formerly worked with the printer now exhibits the same problem and is unable to print. Pattern of behavior is the same. Print job passes through the print queue in normal fashion with no output from printer and no error conditions reported by the printer or Windows. Is this possibly a case of windows "automagically" picking or changing the driver despite all efforts to install the correct driver? In my long IT career I recall instances where the wrong driver file has to be hunted down and manually deleted in order to get Windows to stop using it. Is that perhaps the case here? If so, how can we determine the correct driver file name, and identify the name and location of the "defective or deviant" driver file for removal. Or, other solution? Please help. All efforts are appreciated.

[TEJ1602]

@BartSm

This requires remote assistance.

Please reach out to the HP Support in your region for further course of action.

Hope this helps!

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!