Not being able to cast your phone to a TV is usually caused by network issues, outdated software, or incompatible devices. The most common cause is that the phone and the TV are not on the same Wi-Fi network. Google Help +1
If your phone doesn't detect the TV or you don't see your screen mirrored, it's always a good idea to: Check the TV input/source. Enable screen mirroring manually from your TV's settings. Check if your phone and TV are connected to the same Wi-Fi network.
Verify your Wi-Fi settings: From your Android device, go to Settings Wi-Fi Menu Advanced Scanning always available or Nearby device scanning. Make sure that option is turned on. Confirm your data plan settings: From your Android device, go to Settings Data usage Menu Restrict background data or Data saver.
Cast from Google Cast-enabled apps to your TV
To cast, your TV and casting device need to be on the same Wi-Fi network. If your phone or tablet is using cellular data, switch it over to your home Wi-Fi. Give your router a breather. Your router may just need a brief time-out.
Check that the devices are updated to the latest software and are on the same Wi-Fi network. Allow AirPlay receiving under Settings > General > AirPlay & Continuity on your iPhone and under System Settings > General > AirDrop & Handoff on your Mac.
Connect to your TV
How to cast: A quick start guide
Mirroring is ideal for showcasing presentations or sharing the entire interface, whereas casting offers more flexibility by letting you continue to use your smartphone for other tasks while streaming specific content.
How to Fix Screen Mirroring Not Working
If the devices/apps you're using don't support DRM, then you won't be allowed to mirror content from Apple TV+, Prime Video, Disney+, etc. In that case, you'll see a black screen or a "Blocked" message, which means screen mirroring is not working due to DRM restrictions.
First make sure the Chromecast is properly set up and connected to your TV and the same WiFi network. For more details, visit the Chromecast support page. If you still cannot cast, there may be several potential reasons: Chromecast does not support casting over Virtual Private Networks (VPN).
Screen mirroring issues are usually caused by network restrictions, device or app limitations, or protocol differences. When screen mirroring is not working, the problem is somtimes not the device itself, but how devices discover and communicate with each other on a local network.
Make sure that your device and the TV have the correct time settings. Note: To set the date and time of the TV, refer to the article How to adjust the date and time on the TV. Update the TV to the latest software. Depending on your Android TV menu options, make sure that the Google Cast app is enabled.
From the Chromecast device
Your phone or tablet cannot cast to your Cast-enabled device if it is connected to your mobile network. Your phone or tablet must be connected to a Wi-Fi network. The smartphone, tablet or computer you are using to cast must be on the same home Wi-Fi network as your Cast-enabled device.
How to Enable Screen Casting on Android
What is the difference between Casting and Bluetooth audio? With Chromecast Audio, the music is streamed from the cloud to your speakers via Wi-Fi providing many benefits compared to Bluetooth: Your phone is not tied to what is playing on the speaker.
On your Android device, go to Settings and select the 'Cast' or 'Wireless Display' option. Select your display from the list of available devices.
A: If you encounter any issues while connecting your iPhone to a smart TV, try the following troubleshooting steps: Ensure that both devices are connected to the same Wi-Fi network. Restart your iPhone and smart TV. Update your iPhone's iOS and the apps involved.
Make sure both devices are on the same Wi-Fi network.
To mirror your screen to your TV, both your mobile device and TV or streaming device need to be connected to the same Wi-Fi network. Check the Wi-Fi settings on both devices and make sure they are connected to the same network.