Many people (including myself) have found their "sonicare" toothbrush break within 6 months. I got mine replaced under warranty, and it broke again after 1 year.
Why does a 3 year old video for repairing Sonicare toothbrush have 425K reviews on YouTube: https://www.youtube.com/watch?v=o3PBPU2jXbo, with 2.8K upvotes and 192 downvotes. It breaks because a screw goes loose inside the toothbrush.
I recommend you avoid Phillips electric toothbrush completely. I used a oral-B electric toothbrush for at least 8 years with no issues. And Phillips breaks in 6 months.