phone stopped vibrating

[en0x#AC]

Hi,
Today my phone just stopped vibrating,
I did not change any settings etc, when i pres windows back or search buttons the vibration is not there, when somebody calls me it does not vibrate too....

Even when i'm turining the phone on is not vibrating on the beginning. I have no idea what has happened and i'm not feeling like resetting the phone off.

I have latest update.
The phone was fine since I got it and today it just stopped vibrating

 

[en0x#AC]

I tapped the phone on the back few times and it looks like vibration is working again. I wrote to htc support to see it they can fix it or replace.