Can’t find Chromecast when trying to link to a speaker or display

If you’re trying to connect your voice-supported TV or speaker(Chromecast, Chromecast Audio, or speakers or TVs with Chromecast built-in) to Google Nest or Home speaker or display and are unable to find or see these devices, try these troubleshooting steps.

Note:

1. Some devices aren't using Cast technology and therefore can't be linked to a speaker or display. The following devices aren't using Cast technology, even though the experience may be similar to casting: 
   1. Smart TVs that aren't Android TV devices or TVs with Chromecast built-in
   2. Roku products, Apple TV products, and Amazon Fire TV products
   3. Sonos 
2. If you're receiving an error message saying your device is "unsupported", make sure you have a voice-supported TV or speaker. Important: TVs and speakers with Chromecast built-in and must be using Cast firmware version 1.21+. Here's how to check which firmware version you're using. 

Step 1. Make sure the Chromecast device is powered on

Step 2. Make sure the Chromecast device is connected to the same Wi-Fi network as your phone and speaker or display

Check what Wi-Fi network your phone is connected to

1. ​On the Home screen, tap Settings  Wi-Fi. 
2. The Wi-Fi network that says "Connected' is the Wi-Fi network your phone is connected to. 
3. To change the Wi-Fi network, tap a network from the list.

Check what Wi-Fi network your speaker or display and Chromecast​ device are connected to

1. Make sure your phone or tablet is connected to the same Wi-Fi or linked to the same account as your speaker, display, Chromecast, or Pixel Tablet.
2. Open the Google Home app .
3. Tap and hold your device's tile.
4. Tap Settings   Device information.
5. To change the Wi-Fi network, next to "Wi-Fi," tap Forget  Forget Wi-Fi network. 
6. Go back to the home screen, and follow the steps to set up your device.

Step 3. Verify settings

Turn on location services and enable location permissions for the Google Home app

1. Tap Settings .
2. Tap Security & Location Location  Use location  return to Home screen.
3. Tap Settings  Apps & notifications  Google Home app   Permissions.
4. Next to "Location," make sure the slider is on (toggled to the right and blue).