I have gone through your Post and would like to help
Print a Quality Test Report and check if black is printing
Load plain white U.S. letter or A4 size paper in the tray.
On the control panel home screen, press the Setup icon .
Press the button next to the Down Arrow until Reports displays next to OK.
Press the button next to OK to select Reports.
Press the button next to the Down Arrow until Print Quality Report displays next to OK, and then press the button next to OK. The report prints.
Figure : Example of the report
If black does not print please contact HP Support in your Region for Service Options
1) Click on this link - www.hp.com/contacthp/
2) Select your product type below.
3) Enter the serial of your device.
4) Select the country from the drop-down.
5) Select the chat or get phone number options based on your preferences.
6) Fill the web-form and proceed further.
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