Hello and welcome aboard. There are a few troubleshooting steps that you can perform. 1.) Remove and reinsert the battery. 2.) Check in Wireless & Networks to see if "Mobile Network" box has a check inside of it. 3.) Reset the device to its factory default settings. 4.) Contact your service provider for help with this issue. Also, you can check in with the other users of this device. They might have other solutions that might help. I hope this place prove useful to you.
