When you have a CDMA Blackberry and your using it with a sim card , Storm, Tour, Storm2 ect you will sometimes have an error on your screen saying Service Required or Activation Required. To remove this Error Message do the following:
1. On the main screen of the phone, press ##000000
2. For the Mobile Directory Number, put in your phone number in there.
3. After you have done that, press the menu button to save the options and the phone will automatically restart
Notes: Be Sure the phone is not saying low battery when this is attempted contact BlackberriesRUS for more info.