I've never seen any Chromecast advertising that implies it only gets power over HDMI. All of the media on Google's Chromecast site show either both HDMI/Aux and

I've never seen any Chromecast advertising that implies it only gets power over HDMI. All of the media on Google's Chromecast site show either both HDMI/Aux and USB plugged in or nothing plugged in. Pretty much any TV now has a USB port whether it be for media playback or for updating the firmware of the TV on older ones so its not a huge deal to have to plug it. Even the first release of the device clearly mentioned it needing USB power. https://www.youtube.com/watch?v=YRu18f2GRQo&t=41m22s https://www.youtube.com/watch?v=YRu18f2GRQo&t=41m22s