Vibration getting weaker

[Guest csc12345678]

My O2 Graphite is about 1.5 year old. Lately, I notice that the vibration is getting weaker. What are the possible reasons for this ? Can I solve it myself without going to the service centre ? Thanks.

[Guest awarner (MVP)]

The motor that make the vibration could technically be getting worn, but I have not heard of this before?

Only other thing I can think of is a battery with low charge or a possible dust build up but I would think both of those options were unlikely.