Brother invalidates its laser cartridges after a certain number of revolutions irrespective of how much toner is left. You used to be able to override this manually but they removed that in a software update recently. Am livid. If you know different do you mind sharing what model you have?
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.