I would follow these steps for when you're unable to locate a Wi-Fi network on your iOS devices:
- Be sure you're in range of your Wi-Fi router (access point).
- Tap Settings > Wi-Fi and turn Wi-Fi off and on. If your W-Fi setting is dimmed, follow these steps.
- Confirm that your Wi-Fi router and cable or DSL modem are connected to power, turned on, and connected to the Internet. If not, refer to your network administrator or Internet service provider (ISP) for assistance.
- Restart your iOS device.
- Tap Settings > Wi-Fi and locate the Wi-Fi network to which you're connected.
- Tap i and Forget this Network.
- Try to connect to your desired Wi-Fi network.
Note: You may need to enter your Wi-Fi password again if your network requires one.
- Turn your Wi-Fi router off and on2. If your ISP also provides cable or phone service, check with them before attempting this step to avoid interruption of service.
- Update your device to the latest version of software.
- Update your Wi-Fi router to the latest firmware2. For AirPort Base Stations, install updates using the AirPort Utility.
- Verify that the network is available by tapping Settings > Wi-Fi and choosing from the available networks.Note: It may take a few seconds for the Wi-Fi network name to appear.
- Move closer to your wireless router (access point) and attempt to locate the Wi-Fi network.
- If you do not see the network you would like to join, you may be attempting to connect to a hidden network. Learn how to join a hidden network.
- Supported Wi-Fi configurations vary by iOS device model. Find out which standards your device supports3.
- Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings including:
- previously connected Wi-Fi networks and passwords
- recently used Bluetooth accessories
- VPN and APN settings
There are more recommendations in that above article, so if none of those work I would check out the other options within.
Have a great day,