Try the following in order: (Note: If any step resolves the issue, STOP, do not go on to the next step.)
- Restart your iPhone: To restart your (perform a soft reset) iPhone, press and hold the sleep/wake button while pressing and holding the Home button. When you see the Apple logo, release both buttons. (Note: This will NOT delete any data or apps, nor change any of its settings.)
- Reset your iPhone's Wi-Fi settings: Settings > General > Reset > Reset Network Settings
- Perform a "Reset All Settings" reset: Settings > General > Reset > Reset All Settings
- Reset your iPhone to its factory default settings: Settings > General > Reset > Erase All Content and Settings
- Restore you iPhone: To restore your iPhone, connect it to your computer. When the iPhone appears in the iTunes source list, click the Restore button on the Summary tab. Note: This will erase all of your data and media and resets all of the iPhone's settings. You will need to restore it from a previous backup from either iTunes or iCloud.
- Make aGenius Bar appointmentat your local Apple Store or take it to anApple Authorized Service Provider.
Also check out the following article to see if it can help:
AirDrop not working? Here's the fix! - iMore
