Deskjet 3510 USB printing: paper feeds, but blank

[Mance]

Hello Community! I just got this hand-me-down HP3510 all in one printer.  It is connected by USB to my Mac running 10.13 (NOT wireless, my wireless router does not have the connection button).  Printer is turned on and light is on.  It will feed the paper through, look like it is printing, the cartridge carriage makes all the right moves, but it will not print.  Here's what I have tried so far: 

1) checked ink — both cartridges are original HP, appear in system, and are over half full

2) Restarted computer, printer, etc. Re-installed driver

3) Hard restart of printer by unplugging, waiting, plugging in

4) Searching this forum — only answers are for Windows

5) HP Chatbot

6) Aligning cartridges, printing diagnostic page, printing test page (none of these actually print)

Thank you!

[8lives]

Try a new black cartridge.

[Mance]

Thank you for answering, but I am not going to pay $40 for a new black cartridge when the one I have is more than half full. They are original HP cartridges, and I have removed and reinstalled them. Surely the reason we pay so much for original cartridges is so that we don't have to throw them away.

Neither colour nor black&white printing works.

I have now tried printing over WiFi too, and that also does the same — sounds like it is printing, but no ink comes out. 

Any other ideas? 

Thanks

[8lives]

How long was the printer sitting unused?

[Mance]

Thanks for trying again! 

It was only unused for about a week. When I took out the cartridges and put them back in, as an early troubleshoot, they still had liquid ink showing. 

Just to be clear, if I knew the problem was a faulty black cartridge, of course I would replace it. But I am afraid I will replace that, and it won't work, and then I'll replace the other, and it won't work, and then I will have well over the value of ink that I could buy a new printer (with new cartridges!) for.

[8lives]

A simple test would be to touch the printhead(s) to a paper towel & see if there is a solid streak of ink.

[Mance]

The colour cartridge puts quite a lot of ink on tissue, but the black only a less-wet line. The supply showed it was three-quarters full before, but now shows half full. 

If the black cartridge is malfunctioning, would colour printing still work? 

thanks

[8lives]

Yes it should just remove the black cartridge.

[Mance]

Tried, that, same behaviour.  Any more ideas?

[8lives]

Looks like the printer is bad.