Finally found the manual for my Series 8000. To reset the cutter life timer hold the power button for 7 seconds when turning the razor off. To lock the razor (for travel perhaps?) hold the power button for 3 seconds. Then 3 seconds at your destination to turn it on the first time.

Uh, how does one reset the cutter life timer? Many Norelco shavers have an annoying beep after so many hours of shaving to demand the cutters be replaced. Guessing the instructions in the new cutters say how to reset but that means I would have to purchase new cutters.