Black ink not printing on my HP Photoshop 6520

[Malcolm8]

My printer is not printing black ink.  I've run the diagnostics and the print quality diagnostic says the ink levels are okay.  I've tried two different brand new HP ink cartridges.  I've cleaned the printhead twice and have also aligned the printer.   On the Print Quality Diagnostic, the cyan, magenta and yellow show up (three shades for each); the black box is empty - no ink at all.  However, the text of the diagnostic page is in black. 

Please help!  This is very frustrating.

[sabretooth04]

Try here.

https://support.hp.com/us-en/product/HP-Photosmart-6520-e-All-in-One-Printer/5169038/model/5169040/d...

Let us know.

[Malcolm8]

I've already been through all of the steps suggested on the website.  It's still not printing black.

[sabretooth04]

Check all all the Youtube videos here.

https://www.youtube.com/results?search_query=Photosmart+6520+print+head

Search for more if needed.  If no joy your printer is toast.

[Malcolm8]

I've already tried all of the steps suggested on the website.  It's still not priniting black.  That's why I've posted here on this forum.  What's the next step?  Thanks.