Many readers contact me and ask for help with their APN settings for their Android phone after they tried setting their APN setting but it didn’t work. The first thing I recommend is to try a Reset To Default and then try re-entering their APN settings. Enough readers have told me that this step solved the problem, so its worth trying. I am not sure whether the Reset to Default actually clears something in the phone itself, or whether they made a mistake entering the APN settings the first time and corrected it the second time.

Resetting to Default is easy.

From your APNs screen in Settings, choose the Reset To Default menu item. The phone will remove all the APN from your phone and add one or more default settings that it thinks are appropriate for the SIM you have in your phone. After this step, edit each APN in the list by tapping on it, From the menu, choose Delete APN. Repeat for each APN in the list, until the list is empty. Next, Tap the + to create and edit a new APN and reenter the APN settings for your wireless provider.

These are the steps on the Google LG Nexus 5 using Android 4.4.4. The steps may differ depending on your phone model and Android version but hopefullly will be similar enough to follow.

1. Tap Settings
   
2. Tap More
   
3. Tap Mobile Networks
   
4. Tap Access Point Names
   
5. Tap Menu (3 vertical dots)
   
6. Tap Reset to Default
   
7. Screen displays Restoring default APN settings

8. Screen displays Reset Default APN settings completed.
   
9. Tap ATT Phone (first APN in the list)
   
10. Tap Menu (3 vertical dots)
    
11. Tap Delete APN
    
12. Repeat steps 9-11 for any remaining APNs in the list
13. When the list is empty, Tap Add (plus in circle)

14. Edit your new APN and Tap Save when done entering your APN settings.