Sprint EVO 4G data reset procedure

In order to get your data working again after an outage of 3G or 4G you need to do the following in sequence:

  1. Phone this number: ##3283#
  2. Hit "EDIT" - it will prompt for a password
  3. Hit 287804
  4. Hit "OK"
  5. Select "DATA PROFILE"
  6. Go to Menu --> Restore
  7. Hit "OK" [Twice]

It will reboot, and do stuff...
Then, once it has fully rebooted, go to: Menu/Settings/System Updates/Update Profile
Once that is done, your data connection via 3G or 4G should be repaired.