No matter whom we surveyed in the circle - at least every second, which also uses Sonicare, had the same problem: Only allows the handpiece not turn immediately or switched easily from. Later the handpiece jumping at night to simply and deafened in the bathroom sink and on shelves until it finally complete the service stops - usually shortly after the warranty has expired, often, however, even after one year.
This is due to the ingress of water and the way in which the handpiece is cleaned. Who (as we initially) every 3-4 cleaning decreases the brush and then the toothpaste residues away, not avoid removing permanently dried residues with a brush. However, the rubber seal is heavily loaded at the push-pin. Later on penetrate smallest quantities of water that lead gradually to short circuits and failure of the electronics inside.
Therefore, we now clean handpiece and brush approach after each brushing by the brush is removed and handpiece and brush are briefly rinsed under running water. Then nothing can permanently dry and the handpiece must not be cleaned separately with brush.
Since we do this to keep our handpieces already more than 2 years - what you would expect at purchase price also.