This article helps troubleshoot making or receiving calls on your Apple iPhone 4s.

You may have issues with calls if you have:

• A low signal strength
• Network impairment
• Equipment issue

These steps help identify and resolve the underlying cause. After completing each step, test to see if the issue is fixed. If not, continue to the next step.

1. Verify airplane mode is turned off.

   Airplane mode is a feature that prevents your device from sending or receiving a wireless transmission.

   1. From the home screen, tap Settings.
   2. Tap the Airplane mode slider to OFF.

2. Verify that mobile data is enabled.

   1. From the home screen, tap Settings.
   2. Tap Cellular.
   3. Next to Cellular Data, tap the toggle switch to enable mobile data.

3. Verify if coverage is available at your current location.

   If your Apple iPhone 4s has low signal strength, see if your location is within Sprint voice coverage on the Sprint coverage map.

4. Reset the network settings.

   Resetting the network settings reconnects your Apple iPhone 4s to the Sprint network and does not erase any of your content or data.

   1. From the home screen, tap Settings.
   2. Scroll to and tap General.
   3. Scroll to and tap Reset.
   4. Tap Reset Network Settings.
   5. Tap Reset Network Settings to confirm.
   6. Your Apple iPhone 5 restarts.
   7. Test your device to see if the issue is resolved.

Note: To optimize device performance, be sure your Apple iPhone 4s is running the most recent device software. Check for software updates.

If you're still having issues, dial *2 on your phone or dial 855-639-4644 to reach Sprint Prepaid Customer Care.