Did you clean the neck of the waste toner bottle well? If you look at the neck there are two clear looking circles that will have to be super clean. I've always punched holes with a needle nose pliers so that the photo-cell sensors don't have trouble connecting. The blockage of the beam indicates the bottle is full when actually the neck is lightly covered with waste toner. The copier has never given this trouble after putting these holes in the circles. You should only have to cycle the power to clear the code after the neck is cleaned. Good luck.