iPhone vibration mode is necessary for many people. On many occasions where it is not appropriate to turn on the ringtone, we will set the phone to vibration mode. So that even if there is a call or message, there will be the prompt. You may be annoyed when your iPhone vibration fails to work suddenly and you can't find out the obvious cause. What you want to do first is to repair your iPhone in Apple store. In reality, the reason for this problem is various. Not all the issues about iPhone vibration not working need to be repaired in the Apple store. Here are specific ways to solve the problem in different situations.