I was having a difficult time getting the top piece to lock into place and unlock until I discovered that the spindle on the inside of the top piece comes off and can be washed, as it was full of carrot pulp underneath it which was causing the top piece to be raised up too high to open and close easily. Once I figured this out, and removed the pulp the top piece opens and closes easily, and the juicer works just fine. It does a great job of juicing, even hard things like carrots, as all you need to do it to cut them up, and dump them down the top, and the machine does all the rest. I use an extra carrot to scrape down the sides of the top piece to get the rest of the pulp out. Great juicer for the price.