HP Smart Tank 615 unused for 10 months. "Clean cartridges" not working. How to clean better?

[wileybones]

HP Smart Tank 615 sat unused for 10 months due to pandemic evacuation. Printheads may have dried ink interfering with print quality. Have run all tools, esp. cartridge cleaning multiple times, but still unsatisfactory. How can I better clean the printheads?

[Valsimot]

10 month is a very long period for a printer to be left unused, getting back the print quality will be very hard close to impossible.

You can try to remove the printheads and soak them ( bottom part) in hot water for a few seconds hoping that hot water will dissolve dried ink, repeat the steps if you get an increase in print quality.

In a worst-case scenario, you will need to replace both printheads.

[wileybones]

I was hoping to do what you suggest, but unless the printer is registering a specific problem with the printheads, they don't slide over to where I can open the latch to remove them. I keep running the "Clean cartridge" tool, and the print quality has improved, but it isn't what it should be.