My CLP-550N thinks the waste bin is full when it is actually a new bin. So far, the best advice I've seen is to remove the front of the printer and hotwire the "black" side of the sensor to make it say it's always an empty bin. 1) I'd love to see the process of removal of the front. 2) If there is an alternate solution to the false "waste bin full / not installed" message, I'd love to hear it.