I've had the same problem for the last couple of days... I've got a workaround, but not a permanent fix...
If you look at the water reservoir, you'll see a small black square close to the water outlet that moved around freely inside a small enclosure. That black square is a magnet that triggers a switch inside the coffee maker. When there's water in the reservoir, it is supposed to sort of float to the top of the small enclosure. When the reservoir is empty, it will drop down and disengage the internal switch. In my case, the black square doesn't 'float' anymore even when the reservoir is full.
I took a small hammer with a metal head, stuck it in the water reservoir close to the black square and made sure it's 'pulled up'. The internal switch will engage and the coffee maker will detect that the reservoir is full. Of course if you run out of water now, the coffeemaker will still think the reservoir is full, so pay close attention to how much water you actually have left in the reservoir. Not sure what will happen if it keeps pumping when the reservoir is empty.
Maarten, June 2010
