I have a Sonicare that rattled the head off within a half year of buying it. I took it apart and it was due to a screw with no thread lock being the only thing holding everything together. On a vibrating part.
Put some thread lock on it and it’s been totally fine since, but that seems like it’s intentionally planned to fail. Good job, Philips.
I had the same problem. Sent it back to them and they fixed it, but perhaps I should have a look inside. They did imply I'd dropped it when I'd done nothing of the sort.
They are actually fairly repairable once you manage to open the watertight enclosure, which requires patience and a fair bit of violence. Switching out the cell is really easy once the battery starts dying.
The different Sonicares also share many of their parts, makes replacing broken pieces possible if you ever do drop one.
Put some thread lock on it and it’s been totally fine since, but that seems like it’s intentionally planned to fail. Good job, Philips.