As I understand the Photosmart 7515 just quit printing line type and it doesn't work though you've replaced the black ink cartridge,
No worries, as I'll be glad to help you, that said, I'll need a few more details to dissect your concern & provide an accurate solution:
Have you ensured the ink cartridges are genuine HP branded?
Did you ensure none of the ink levels are at low?
While you respond to that, here's a few things you can do:
Step 1: Use genuine HP ink cartridges
HP recommends that you use genuine HP ink or toner supplies. HP cannot guarantee the quality or reliability of non-HP or refilled cartridges. If you do not use genuine HP cartridges, the steps in this document might not resolve the issue. To check the authenticity of your cartridges, go to hp.com/go/anticounterfeit.
Step 2: Check estimated ink levels
Check estimated ink levels to see if any ink cartridges are critically low or empty. Ink must be available in each ink cartridge to run printhead-servicing tasks and prevent nozzles from clogging with ink.