From AT&T's support website... 
Any of the following physical symptoms automatically suggest a defective Wi-Fi gateway:
• Wi-Fi gateway is smoking.
• Wi-Fi gateway is making a loud humming noise.
• Wi-Fi gateway is melted and misshapen.
• Wi-Fi gateway rattles inside when shaken.
Any of the following physical symptoms automatically suggest a defective Wi-Fi gateway:
• Wi-Fi gateway is smoking.
• Wi-Fi gateway is making a loud humming noise.
• Wi-Fi gateway is melted and misshapen.
• Wi-Fi gateway rattles inside when shaken.
loves it.
...none of these are happening to you, right?
takes notes
I hope none of these happen to me, but should it be so I promise that going to AT&T's support website will not be my first course of action.
I have question, actually... For what reason would one be shaking a wi-fi gateway to even discover that it rattles? NEVER EVER SHAKE A GATEWAY.