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Man-in-the-Middle PCB Unlocks HP Ink Cartridges
(hackaday.com)
This is a most excellent place for technology news and articles.
There is an official way to override this. In mine it’s pressing 7 times some button. I can’t
Remember what it’s called, but it’s in the manual. The mode essentially lets you print until the cartridge is empty
That's what I used to be able to do. It was pressing the back and cancel buttons in some combination brought up a hidden menu where you could reset the toner levels. You can still bring the menu up on mine but now it ignores any reset you do.