E02 indicates that the cover is not closed. The common wall-breaking machine needs to fix the upper cover on the mouth of the cup and rotate the cover counterclockwise so that the slender part protruding from the cover is aligned with the upper part of the handle of the cup. Self-cleaning model reference picture: First, align the unlocking mark on the upper cover of the grinding chamber with the black spot on the machine, press down the upper cover and rotate it clockwise, so that the locking mark on the cover is aligned with the black spot on the machine, indicating that it is installed in place.