While the Chromecast is plugged into the TV and powered, press then hold the button on the back of the Chromecast. The LED should start to blink yellow.
When the LED light turns solid white, release the button, and the Chromecast should then reset.
We haven't heard from you in a while so we’ll be locking this thread if there’s no update within 24 hours. If you still need help, please feel free to start a new thread and we'll be happy to help.
Thanks for the help here, Ashepherdson and Jeran.