Using a small flat screwdriver allows the shell of the Toothbrush pry and pull the bottom of the inner life. The top of the Complete is a small Phillips screw. This seems (Philips intentionally or unintentionally) to resolve over time. Simply tighten again - done!
Of course, the toothbrush and Philips of me gets only one star - the repair takes less than 2 minutes - yet maintains Philips, the repair is more expensive than a new unit. And that there is no alternative to this loose screw in all the years and complaints, deserves no star.