Check the following items:

1. Check if the Wi-Fi network is enabled on your device.
2. Verify that your router is turned on.
3. Check if the Wi-Fi network is visible on your device.
4. Ensure that your device is within the Wi-Fi range.
5. Perform a ‘Forget’ on the network and re-connect.
6. Try to restart the router.
7. Ensure that the password is correct to connect to the network.