Photosmart 7520 won't do anything after cleaning printer head

[AdamHy]

All my ink cartridges were low and black was not printing.  I replaced all 5 cartridges.  The level showed as high, and test pages worked except black still did not print.  Following your directions, I cleaned the printer head (wiping, putting in water for ten minutes, etc - lots of ink came off).  Reinstalled printer head and cartridges.  Message: "printer head missing or installed incorrectly."  Reinstalled.  Same message.  Restarted printer.  No message.  On the panel, tried "Clean cartridges" "Print quality report" and "Align printer" and nothing happens: no printer head moving, no error message.  Turn it off and on a couple of times, and also try unplugging it a couple of times, replugging.  No change.

Tried sending a job to print from a computer.  No response.  Removed printer head to clean again, the other way - wiping the electrical things, etc.  More ink comes off.  Reinstall.  

Message: "printer head missing or installed incorrectly."   Turn printer off, turn it on.  Message: "printer head missing or installed incorrectly."   Try reinstalling it, it comes back to home panel .  On the panel, tried "Clean cartridges" "Print quality report" and "Align printer" and nothing happens: no printer head moving, no error message.  

The next step would seem to be buying a new printer head, but this is the unit's second printer head, purchased in Jan 2019.  Given HP's use of ink, quickly emptying and crazy cost, it doesn't really seem worth it to pay $77 for a new printer head (whcih HP doesn't even sell anymore.)  

Any ideas?  Time for a new printer?  The only issue had been that black wasn't printing, and now it doesn't work at all.