lj4250 not recognizing new toner

[cloughran]

I have installed a new HP toner,but the printer is still displaying the replace toner message.

This problem is on going. In the past it has had a compatible toner installed and this worked intermittantly. But have tried 3 new HP toners, none working. Any ideas

[MichaelTech]

The toner reader may be dirty. It sits at the top right of the toner cavity.
Ensure that it swivels easily.
Try a firmware upgrade.