In some rare cases , the setting to turn Wi -Fi on your iPhone , iPad or iPod touch may appear gray, or dimmed. You may see the following by pressing Settings> Wi -Fi .
If this happens , you can not activate the Wi -Fi , and when you try, the device does not respond . If you use iOS 7, it would appear that the Wi -Fi is turned on or off in the Control Center , but the Wi -Fi will not respond.
resolution
Follow these steps to resolve the problem:
Restart your iOS device.
Make sure airplane mode is disabled by pressing Settings> Airplane Mode .
Resets the network settings by tapping Settings > General > Reset> Reset Network Settings .
This action will reset all network settings, including records of Bluetooth pairing , passwords for Wi -Fi , VPN , and APN settings .
Make sure your device is running the latest version of the software . To do this, connect it to your computer and check for updates in iTunes.