Connect the switch with the cast action
Begin with the television showing another input, such as its tuner or an external device. Note which receiver was chosen in the sending application and whether starting the cast moved the television to the Google streaming device’s HDMI port. The selected receiving device matters in a home with several similar room names.
Google describes that source change as CEC behaviour and says some compatible televisions can also turn on when casting starts. That does not mean every television has the same wake capabilities or uses the same setting name. Keep the physical TV model and selected port with the observation.
Check the power and CEC context
Google’s guidance says the streaming device must use wall-outlet power for this function, rather than the television’s USB port. If the receiver loses power with the TV, compare that supply condition before concluding that a previously visible cast receiver has permanently failed.
The television’s CEC setting can have a manufacturer-specific name, such as Samsung Anynet+, LG SimpLink or Sony BRAVIA Sync. Use the exact television manual to inspect the relevant control. Avoid changing every HDMI option merely because a tutorial for another brand uses a different label.
Separate input selection from playback
After the television selects the expected HDMI port, inspect the receiving screen. An input switch shows that a control action occurred; it does not prove that the selected application accepted the programme or completed its own playback. Preserve those as separate results in your notes.
If the wrong screen wakes, verify the receiver selected by the sender. If the correct device is selected but CEC commands fail, Google also directs viewers to device and TV firmware and the television’s CEC state. Report the sender action, receiver name, TV input before and after, power source and resulting picture. Those facts distinguish intended source switching from a separate connection or programme problem.